Sulfur chelated ruthenium compounds useful as olefin metathesis catalysts

Abstract

Sulfur chelated ruthenium compounds represented by the following formula: ##STR00001##
wherein M indicates the ruthenium metal bound to a benzylidene carbon; R represents C.sub.1-C.sub.7 alkyl group or optionally substituted aryl; X.sub.1 and X.sub.2 each independently represent halogen; Y.sub.1 and Y.sub.2 each independently denote unsubstituted or alkyl-substituted phenyl; and Z independently represents hydrogen, electron withdrawing or electron donating substituent, with m being an integer from 1 to 4, and processes and compositions related thereto.

Claims

1. A sulfur chelated ruthenium compound represented by the following formula: ##STR00037## wherein M indicates the ruthenium metal bound to a benzylidene carbon; R represents an optionally substituted aryl; X.sub.1 and X.sub.2 each independently represent halogen; Y.sub.1 and Y.sub.2 each independently denote unsubstituted or alkyl-substituted phenyl; and independently represents hydrogen, electron withdrawing or electron donating substituent, with m being an integer from 1 to 4.

2. A compound according to claim 1 represented by Formula IA: ##STR00038## wherein R is an optionally substituted aryl.

3. A compound according to claim 2, wherein R is an optionally substituted aryl selected from the group consisting of phenyl, naphthyl and pyrenyl.

4. A compound according to claim 1, wherein one Z substituent is nitro and the others are hydrogen.

5. A composition comprising an olefin starting material dissolved in an organic solvent together with a catalytically effective amount of the compound of Formula I as defined in claim 1, wherein said composition is chemically stable at room temperature, such that the conversion of the olefin starting material through metathesis reaction into a product is substantially prevented at room temperature.

6. A composition according to claim 5, wherein the compound of Formula I is a compound of formula IA as defined in claim 2.

7. A process for preparing a metathesis reaction product, which comprises subjecting an olefin to a metathesis reaction in the presence of a catalytically effective amount of a sulfur chelated ruthenium compound represented by the following formula: ##STR00039## wherein M indicates the ruthenium metal bound to a benzylidene carbon; R represents an optionally substituted aryl; X.sub.1 and X.sub.2 each independently represent halogen; Y.sub.1 and Y.sub.2 each independently denote unsubstituted or alkyl-substituted phenyl; and Z independently represents hydrogen, electron withdrawing or electron donating substituent, with m being an integer from 1 to 4; and irradiating said catalyst of Formula I with light.

8. A process according to claim 7, which comprises adjusting the irradiation period in order to maximize the amount of the trans isomer of the compound of formula (I) in the reaction mixture.

9. A process according to claim 7, which further comprises terminating the reaction by means of heating the reaction mixture.

10. A compound according to claim 3 represented by the following formula: ##STR00040##

11. A compound according to claim 3 represented by the following formula: ##STR00041##

12. A compound according to claim 3 represented by the following formula: ##STR00042##

13. A process according to claim 7, wherein the catalyst used is represented by Formula IA: ##STR00043## wherein R is an optionally substituted aryl.

14. A process according to claim 13, wherein the catalyst used is selected from the group consisting of: ##STR00044##

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates the thermo-switchable behavior of the catalyst of Formula IA in RCM reaction. Specifically, conversion of diethyl diallylmalonate by RCM using the catalyst IA at room temperature (dashed line) and at 80 degrees centigrade (solid line) is shown.

(2) FIG. 2 illustrates the thermo-switchable behavior of the catalyst of Formula IA in ROMP reaction. Specifically, consumption of norbornene derived monomer by ROMP using the catalyst IA at room temperature (dashed line) and at 80 degrees centigrade (solid line) is shown.

(3) FIG. 3 illustrates the RCM reaction of diethyl diallylmalonate with the catalysts of the invention at increasing temperatures; each 2 h block was kept at constant temperature.

(4) FIG. 4 illustrates a profile of RCM reaction of diethyl diallylmalonate in the presence of a catalyst of Formula I under specific activation-deactivation protocol.

DEFINITIONS

(5) The term aryl means a carbocyclic aromatic system containing one or more rings, wherein the rings may be attached together in a pendent manner or may be fused.

EXAMPLES

(6) Methods

(7) All reagents used were of reagent grade quality, purchased commercially from Sigma, Aldrich or Fluka and used without further purification. All solvents were dried and distilled prior to use. Purification by column chromatography was performed on Davisil Chromatographic silica media (40-6 μm). TLC analyses were performed using Merck pre-coated silica gel (0.2 mm) aluminum (backed)sheets.

(8) Gas chromatography data was obtained using an Agilent 6850 GC equipped with a Agilent 5973 MSD working under standard conditions; and an Agilent HP5-MS column.

(9) NMR spectra were recorded on Bruker DPX 200 or DPX 500 instruments. Chemical shifts, given in ppm, are relative to Me.sub.4Si as the internal standard, or using the residual solvent peak.

Example 1

Preparation of

(10) ##STR00011##

2-(isopropylsulfanyl)benzenecarbaldehyde

(11) 2-fluoro-benzaldehyde (2.00 g, 16.1 mmol), potassium carbonate (2.45 g, 17.1 mmol) and 2-propanethiol (1.35 g, 17.1 mmol) were dissolved in 10.0 mL DMF in a 50 mL round-bottomed flask under dry nitrogen, topped with a reflux condenser. The reaction mixture was heated to 50° C. for 48 h. After cooling the mixture was added to 50 mL of saturated potassium carbonate solution, and the mixture was extracted with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The yellow oil residue of the crude product was further purified by chromatography on silica gel using 95:5 petroleum ether (60-80) and dichloromethane as eluent to afford a yellow oil (2.58 g, 89%).

1-(isopropylsulfanyl)-2-vinylbenzene

(12) Methyl triphenylphosphonium iodide (1.57 g, 3.88 mmol) was dissolved in 25 mL ether in a 50 mL round-bottomed flask at 0° C. under dry nitrogen. To the mixture was added in one portion potassium tert-butoxide (0.47 g, 4.16 mmol) and it was stirred for 10 min at room temperature. 2-(isopropylsulfanyl)benzenecarbaldehyde (0.50 g, 2.77 mmol) was added in one portion at 0° C. and the reaction mixture was stirred for additional 24 h at room temperature. The mixture was added to 50 mL of saturated sodium bicarbonate solution, and then was extracted with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The light yellow oil of the crude product was further purified by chromatography on silica gel using 95:5 petroleum ether 60-80 and ether as eluent to give a colorless oil (0.40 g, 81%).

The Compound of Formula 1a Wherein R is Isopropyl

(13) 1-(isopropylsulfanyl)-2-vinylbenzene (25.0 mg, 0.14 mmol), cuprous chloride (16.7 mg, 0.17 mmol) and (1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (119 mg, 0.14 mmol) were dissolved in 6 mL dichloromethane in a 10 mL round-bottomed flask under dry nitrogen topped with a reflux condenser. The reaction mixture was refluxed for 4.5 h. The resulting mixture was evaporated to dryness. The crude product was purified by chromatography on silica gel using 7:3 n-hexane and acetone as eluent to give a teal solid (48.0 mg, 55%). Two additional byproducts were separated by chromatography, but only one was fully characterized by NMR analysis: the trans-catalyst isomer green solid (8.1 mg, 9%) and additional green solid (14.2 mg). Both spontaneously converted with time to product 1A according to NMR analysis. Crystals suitable for X-ray analysis were obtained by laying hexanes over a solution of 1A in dichloromethane for few days at −18° C.

(14) .sup.1H NMR (500 MHz, CD.sub.2Cl.sub.2): δ 0.76 (d, J=6.5 Hz, 3H), 1.41 (d, J=7.4 Hz, 3H), 1.56 (s, 3H), 2.16 (s, 3H), 2.37 (s, 3H), 2.44 (s, 3H), 2.57 (s, 3H), 2.64 (s, 3H), 3.58 (m, 1H), 3.80 (m, 1H), 3.88 (m, 1H), 4.00 (m, 1H), 4.11 (m, 1H), 5.96 (bs, 1H), 6.79 (d, J=7.5 Hz, 1H), 6.88 (bs, 1H), 7.04 (bs, 1H), 7.12 (bs, 1H), 7.17 (t, J=6.4 Hz, 1H), 7.46 (m, 2H), 17.14 (s, 1H) ppm. .sup.13C NMR (125 MHz, CDCl.sub.3): δ 17.7, 18.7, 19.7, 20.3, 20.9, 21.0, 21.3, 24.2, 39.0, 51.4, 51.6, 123.7, 128.6, 129.4, 129.6, 129.7, 129.8, 130.7, 131.7, 135.0, 135.4, 135.6, 137.3, 137.7, 138.5, 140.3, 140.4, 156.6, 213.6, 285.6 ppm. APCI-MS m/z (M-Cl).sup.+: 607.1 (Calc. 607.15).

Example 2

Preparation of

(15) ##STR00012##

2-(methylsulfanyl)benzenecarbaldehyde

(16) 2-fluoro-benzaldehyde (2.00 g, 16.1 mmol), potassium carbonate (2.45 g, 17.7 mmol) and methyl sodium sulfide (17.1 mmol) were dissolved in 10.0 mL DMF in a 50 mL round-bottomed flask under dry nitrogen, topped with a reflux condenser. The reaction mixture was heated to 55° C. for 24 hr. After cooling, the mixture was added to 50 mL of saturated potassium carbonate solution and extracted with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using 1:1 dichloromethane/n-hexane as eluent to give a yellow oil (2.08 g, 85%). .sup.1H NMR (200 MHz, CDCl.sub.3): δ 2.49 (s, 3H), 7.24-7.58 (m, 3H), 7.80 (dd, J1=7.6, J2=1.4, 1H), 10.25 (s, 1H) ppm.

1-(methylsulfanyl)-2-vinylbenzene

(17) Methyl triphenylphosphonium iodide (1.57 g, 3.88 mmol) was dissolved in 25 mL ether in a 50 mL round-bottomed flask under dry nitrogen. To the mixture was added in one portion at 0° C. potassium tert-butoxide (0.47 g, 4.19 mmol) and it was stirred for 10 min at room temperature. 2-(methylsulfanyl)benzenecarbaldehyde (2.77 mmol) was added in one portion at 0° C. and the reaction mixture was stirred until complete disappearance of the reactants (2 hr) at room temperature (followed by TLC). The mixture was added to 50 mL of saturated sodium bicarbonate solution, followed by extraction with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using petroleum ether 60-80 as eluent. Yield: 0.33 g, 79%, colorless oil. 1H NMR (200 MHz, CDCl.sub.3): δ 2.43 (s, 3H), 5.32 (dd, J1=10.9, J2=1.2, 1H), 5.67 (dd, J1=17.4, J2=1.2, 1H), 7.05-7.26 (m, 4H), 7.46 (d, 1H) ppm.

The Compound of Formula 1A Wherein R is Methyl

(18) 1-(methylsulfanyl)-2-vinylbenzene (0.14 mmol), cuprous chloride (16.2 mg, 0.16 mmol) and (1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (119 mg, 0.14 mmol) were dissolved in 6 mL dichloromethane in a 10 mL round-bottomed flask under dry nitrogen topped with a reflux condenser. The reaction mixture was refluxed for 24 h. The resulting mixture was evaporated to dryness and the crude product was purified by chromatography on silica gel using 7:3 n-hexane and acetone as eluent. Yield 44 mg (51%) grayish blue solid, .sup.1H NMR (500 MHz, CD.sub.2Cl.sub.2): δ 1.58 (s, 3H), 2.16 (s, 3H), 2.37 (s, 3H), 2.41 (s, 3H), 2.47 (s, 3H), 2.50 (s, 3H), 2.64 (s, 3H), 3.82-3.88 (m, 1H), 3.91-3.97 (m, 1H), 3.99-4.05 (m, 1H), 4.11-4.17 (m, 1H), 6.03 (s, 1H), 6.82 (dd, J1=7.9, J2=1.2, 1H), 6.93 (s, 1H), 7.05 (s, 1H), 7.12 (s, 1H), 7.16 (dt, J1=7.3, J2=1.2, 1H), 7.47 (d, J=7.3, 1H), 7.51 (dt, J1=7.9, J2=7.3, J3=1.2, 1H), 17.00 (s, 1H) ppm. .sup.13C NMR (125 MHz, CD.sub.2Cl.sub.2): δ 17.57, 18.21, 18.90, 19.15, 20.46, 21.20, 21.51, 51.70, 51.81, 123.85, 128.83, 129.47, 129.62, 129.80, 129.84, 129.89, 131.01, 131.85, 135.85, 137.06, 138.06, 138.87, 140.38, 140.41, 140.64, 155.32, 214.62, 285.55 ppm. FAB-MS: M+ calc. 614.1. found 614.1, [M-Cl]+ calc. 579.1. found 579.1.

Example 3

Preparation of

(19) ##STR00013##

2-(ethylsulfanyl)benzenecarbaldehyde

(20) 2-fluoro-benzaldehyde (2.00 g, 16.1 mmol), potassium carbonate (2.45 g, 17.7 mmol) and thioethanol (17.1 mmol) were dissolved in 10.0 mL DMF in a 50 mL round-bottomed flask under dry nitrogen, topped with a reflux condenser. The reaction mixture was heated to 55° C. for 3 days. After cooling, the mixture was added to 50 mL of saturated potassium carbonate solution and extracted with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using 2:1 dichloromethane/n-hexane as eluent to give a yellow oil (1.94 g, 72%). .sup.1H NMR (200 MHz, CDCl.sub.3): δ 1.37 (t, J=7.5, 3H), 2.99 (q, J=7.5, 2H), 7.26-7.56 (m, 3H), 7.84 (dd, J1=8.0, J2=1.7, 1H), 10.37 (s, 1H) ppm.

1-(ethylsulfanyl)-2-vinylbenzene

(21) Methyl triphenylphosphonium iodide (1.57 g, 3.88 mmol) was dissolved in 25 mL ether in a 50 mL round-bottomed flask under dry nitrogen. To the mixture was added in one portion at 0° C. potassium tert-butoxide (0.47 g, 4.19 mmol) and it was stirred for 10 min at room temperature. 2-(ethylsulfanyl)benzenecarbaldehyde (2.77 mmol) was added in one portion at 0° C. and the reaction mixture was stirred until complete disappearance of the reactants (22 hr) at room temperature (followed by TLC). The mixture was added to 50 mL of saturated sodium bicarbonate solution, followed by extraction with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using petroleum ether 60-80 as eluent. Yield: 0.37 g, 81%, colorless oil. .sup.1H NMR (200 MHz, CDCl.sub.3): δ 1.29 (t, J=7.3, 3H), 2.89 (q, J=7.3, 2H), 5.34 (dd, J1=10.9, J2=1.2, 1H), 5.69 (dd, J1=17.4, J2=1.2, 1H), 7.19-7.54 (m, 5H) ppm.

The Compound of Formula 1A Wherein R is Ethyl

(22) 1-(ethylsulfanyl)-2-vinylbenzene (0.14 mmol), cuprous chloride (16.2 mg, 0.16 mmol) and (1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (119 mg, 0.14 mmol) were dissolved in 6 mL dichloromethane in a 10 mL round-bottomed flask under dry nitrogen topped with a reflux condenser. The reaction mixture was refluxed for 24 h. The resulting mixture was evaporated to dryness and the crude product was purified by chromatography on silica gel using 7:3 n-hexane and acetone as eluent. Yield: 80 mg, 91%, teal solid, .sup.1H NMR (500 MHz, C.sub.2D.sub.2Cl.sub.4): δ 1.18 (t, J=7.3, 3H), 1.47 (s, 3H), 2.20 (s, 3H), 2.36 (s, 3H), 2.51 (s, 3H), 2.53 (s, 3H), 2.73 (s, 3H), 2.73 (m, 1H), 3.20-3.27 (J1, J2, J3=7.3; J4=14.0, 1H), 3.78-3.85 (m, 1H), 3.91-4.02 (m, 2H), 4.11-4.18 (m, 1H), 6.05 (s, 1H), 6.78 (d, J=7.3, 1H), 6.95 (s, 1H), 7.01 (s, 1H), 7.12 (s, 1H), 7.18 (t, J=7.3, 1H), 7.50 (m, 2H), 17.15 (s, 1H) ppm. .sup.13C NMR (125 MHz, C.sub.2D.sub.2Cl.sub.4): δ 13.48, 17.08, 18.74, 19.44, 20.17, 20.89, 21.22, 30.80, 50.88, 51.14, 123.30, 128.82, 129.00, 129.05, 129.29, 129.33, 129.64, 130.69, 131.40, 135.06, 135.31, 136.31, 137.58, 138.19, 138.82, 139.40, 139.85, 154.71, 213.81 ppm. FAB-MS: M+ calculated 628.1. found 628.0, [M-Cl]+ calculated 593.1. found 593.1.

Example 4

Preparation of

(23) ##STR00014##

2-(tert-butylsulfanyl)benzenecarbaldehyde

(24) 2-fluoro-benzaldehyde (2.00 g, 16.1 mmol), potassium carbonate (2.45 g, 17.7 mmol) and 2-methyl-2-propanethiol (17.1 mmol) were dissolved in 10.0 mL DMF in a 50 mL round-bottomed flask under dry nitrogen, topped with a reflux condenser. The reaction mixture was heated to 50° C. for 4 days. After cooling, the mixture was added to 50 mL of saturated potassium carbonate solution and extracted with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using 2:1 dichloromethane/n-hexane as eluent to give a yellow oil (1.26 g, 40%). .sup.1H NMR (200 MHz, CDCl.sub.3): δ 1.26 (s, 9H), 7.43-7.63 (m, 3H), 7.96 (dd, J1=6.9, J2=2.5, 1H), 10.76 (s, 1H) ppm.

1-(tert-butylsulfanyl)-2-vinylbenzene

(25) Methyl triphenylphosphonium iodide (1.57 g, 3.88 mmol) was dissolved in 25 mL ether in a 50 mL round-bottomed flask under dry nitrogen. To the mixture was added in one portion at 0° C. potassium tert-butoxide (0.47 g, 4.19 mmol) and it was stirred for 10 min at room temperature. 2-(tert-butylsulfanyl)benzenecarbaldehyde (2.77 mmol) was added in one portion at 0° C. and the reaction mixture was stirred until complete disappearance of the reactants (24 hr) at room temperature (followed by TLC). The mixture was added to 50 mL of saturated sodium bicarbonate solution, followed by extraction with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using petroleum ether 60-80 as eluent. Yield: 0.37 g, 70%, colorless oil. .sup.1H NMR (200 MHz, CDCl.sub.3): δ 1.26 (s, 9H), 5.28 (dd, J1=11.0, J2=1.2, 1H), 5.68 (dd, J1=17.8, J2=1.2, 1H), 7.17-7.67 (m, 5H) ppm.

The Compound of Formula 1A Wherein R is Tert-Butyl

(26) 1-(tert-butylsulfanyl)-2-vinylbenzene (0.14 mmol), cuprous chloride (16.2 mg, 0.16 mmol) and (1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (119 mg, 0.14 mmol) were dissolved in 6 mL dichloromethane in a 10 mL round-bottomed flask under dry nitrogen topped with a reflux condenser. The reaction mixture was refluxed for 24 h. The resulting mixture was evaporated to dryness and the crude product was purified by chromatography on silica gel using 7:3 n-hexane and acetone as eluent. Yield: 65 mg, 70%, grey-asparagus solid, .sup.1H NMR (500 MHz, C.sub.2D.sub.2Cl.sub.4): δ 1.30 (s, 9H), 1.48 (s, 3H), 2.18 (s, 3H), 2.34 (s, 3H), 2.51 (s, 3H), 2.59 (s, 3H), 2.77 (s, 3H), 3.73-3.80 (m, 1H), 3.85-3.91 (m, 1H), 3.93-3.99 (m, 1H), 4.09-4.15 (m, 1H), 5.96 (s, 1H), 6.79 (d, J=7.3, 1H), 6.90 (s, 1H), 7.03 (s, 1H), 7.13 (s, 1H), 7.17 (t, J1=7.9, J2=7.3, 1H), 7.50 (t, J=7.3, 1H), 7.61 (d, J=7.9, 1H), 17.43 (s, 1H) ppm. .sup.13C NMR (125 MHz, C.sub.2D.sub.2Cl.sub.4): δ 17.42, 18.93, 19.59, 20.30, 20.85, 21.10, 30.35, 50.99, 51.17, 53.72, 123.60, 128.56, 128.93, 129.00, 129.22, 129.49, 129.99, 130.70, 132.08, 134.91, 135.38, 136.52, 137.09, 137.58, 137.94, 139.39, 139.71, 155.55, 213.18, 288.80 ppm. FAB-MS: [M-Cl]+ calc. 621.2. found 621.1.

Example 5

Preparation of

(27) ##STR00015##

2-(phenylsulfanyl)benzenecarbaldehyde

(28) 2-fluoro-benzaldehyde (2.00 g, 16.1 mmol), potassium carbonate (2.45 g, 17.7 mmol) and thiophenol (17.1 mmol) were dissolved in 10.0 mL DMF in a 50 mL round-bottomed flask under dry nitrogen, topped with a reflux condenser. The reaction mixture was heated to 80° C. for 24 hrs. After cooling, the mixture was added to 50 mL of saturated potassium carbonate solution and extracted with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using 9:1 petroleum ether 60-80 and dichloromethane as eluent to give a yellow oil (2.46 g, 71%). .sup.1H NMR (200 MHz, CDCl.sub.3): δ 7.07 (dd, J1=7.8, J2=1.2, 1H), 7.27-7.45 (m, 7H), 7.87 (dd, J1=7.3, J2=2.0, 1H), 10.37 (s, 1H) ppm.

1-(phenylsulfanyl)-2-vinylbenzene

(29) Methyl triphenylphosphonium iodide (1.57 g, 3.88 mmol) was dissolved in 25 mL ether in a 50 mL round-bottomed flask under dry nitrogen. To the mixture was added in one portion at 0° C. potassium tert-butoxide (0.47 g, 4.19 mmol) and it was stirred for 10 min at room temperature. 2-(phenylsulfanyl)benzenecarbaldehyde (2.77 mmol) was added in one portion at 0° C. and the reaction mixture was stirred until complete disappearance of the reactants (17 hr) at room temperature (followed by TLC). The mixture was added to 50 mL of saturated sodium bicarbonate solution, followed by extraction with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using petroleum ether 60-80 as eluent. Yield: 0.53 g, 91%, colorless oil. .sup.1H NMR (200 MHz, CDCl.sub.3): δ 5.33 (dd, J1=10.9, J2=1.2, 1H), 5.74 (dd, J1=17.4, J2=1.2, 1H), 7.16-7.65 (m, 10H) ppm.

The Compound of Formula 1A Wherein R is Phenyl

(30) 1-(phenylsulfanyl)-2-vinylbenzene (0.14 mmol), cuprous chloride (16.2 mg, 0.16 mmol) and (1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (119 mg, 0.14 mmol) were dissolved in 6 mL dichloromethane in a 10 mL round-bottomed flask under dry nitrogen topped with a reflux condenser. The reaction mixture was refluxed for 24 h. The resulting mixture was evaporated to dryness and the crude product was purified by chromatography on silica gel using 7:3 n-hexane and acetone as eluent. Yield: 75 mg, 79%, persian green solid. .sup.1H NMR (500 MHz, C.sub.2D.sub.2Cl.sub.4): δ 1.68 (s, 3H), 2.19 (s, 3H), 2.30 (s, 3H), 2.49 (s, 3H), 2.64 (s, 3H), 2.65 (s, 3H), 3.85-3.96 (m, 2H), 4.04-4.10 (m, 1H), 4.12-4.18 (m, 1H), 6.06 (s, 1H), 6.85-7.43 (m, 12H), 17.21 (s, 1H) ppm. .sup.13C NMR (125 MHz, C.sub.2D.sub.2Cl.sub.4): δ 17.32, 18.63, 19.32, 20.02, 20.89, 21.19, 51.15, 51.42, 123.12, 128.16, 128.22, 129.09, 129.12, 129.39, 129.45, 129.48, 129.57, 130.70, 131.76, 133.11, 135.19, 135.23, 135.89, 137.24, 138.27, 138.52, 139.11, 139.61, 154.50, 213.36, 284.95 ppm. FAB-MS: M+ calc. 676.1. found 676.0, [M-Cl]+ calc. 641.1. found 641.0.

Example 6

Preparation of

(31) ##STR00016##

2-(isopropylthio)-5-nitrobenzaldehyde

(32) 2-chloro-5-nitrobenzaldehyde (2.99 g, 16.1 mmol), potassium carbonate (2.45 g, 17.7 mmol) and propane-2-thiol (1.35 g, 17.7 mmol) were dissolved in 10.0 mL DMF in a 50 mL round-bottomed flask under dry nitrogen, topped with a reflux condenser. The reaction mixture was heated to 55° C. for 24 h. After cooling the mixture was added to 150 mL of saturated potassium carbonate solution. The yellow-brown solid was filtered, washed with water and further purified by chromatography on silica gel using 10:1 petroleum ether 60-80 and ether as eluent. Yield: 1.81 g, 50%, yellow solid. .sup.1H NMR (200 MHz, CDCl.sub.3): δ 1.46 (d, J=6.9 Hz, 6H), 3.67 (septet, J=6.9 Hz, 1H), 7.55 (d, J=8.7 Hz, 1H), 8.32 (dd, J=2.5, 8.7 Hz, 1H), 8.66 (d, J=2.5 Hz, 1H), 10.3 (s, 1H) ppm. .sup.13C NMR (50 MHz, CDCl.sub.3): δ 22.5, 36.6, 127.2, 127.4, 127.9, 133.4, 144.7, 150.8, 189.1.

isopropyl(4-nitro-2-vinylphenyl)sulfane

(33) Methyl triphenylphosphonium iodide (1.57 g, 3.88 mmol) was dissolved in 25 mL ether in a 50 mL round-bottomed flask at 0° C. under dry nitrogen. To the mixture was added in one portion potassium tert-butoxide (0.47 g, 4.16 mmol) and it was stirred for 10 min at room temperature. 2-(isopropylthio)-5-nitrobenzaldehyde (0.62 g, 2.77 mmol) was added in one portion at 0° C. and the reaction mixture was stirred for additional 4 h at room temperature. The mixture was added to 100 mL of saturated sodium bicarbonate solution, and then was extracted with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using 4:1 petroleum ether 60-80 and ether as eluent. Yield: 0.50 g, 81%, yellow oil. .sup.1H NMR (200 MHz, CDCl.sub.3): δ 1.37 (d, J=6.6 Hz, 6H), 3.56 (septet, J=6.6 Hz, 1H), 5.50 (dd, J=0.9, 10.9 Hz, 1H), 5.80 (dd, J=0.9, 17.2 Hz, 1H), 7.09 (dd, J=10.9, 17.2 Hz, 1H), 7.40 (d, J=8.7 Hz, 1H), 8.04 (dd, J=2.5, 8.7 Hz, 1H), 8.30 (d, J=2.5 Hz, 1H) ppm. .sup.13C NMR (50 MHz, CDCl.sub.3): δ 22.8, 37.1, 118.4, 120.9, 122.3, 128.2, 132.8, 138.4, 144.5, 145.5.

The Compound of Formula 1A Wherein R is Isopropyl, and Z is Nitro Group

(34) isopropyl(4-nitro-2-vinylphenyl)sulfane (31.3 mg, 0.14 mmol) cuprous chloride (16.7 mg, 0.17 mmol) and (1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (119 mg, 0.14 mmol) were dissolved in 6 mL dichloromethane in a 38 mL close pressure tube under dry nitrogen. The reaction mixture was refluxed overnight. The resulting mixture was evaporated to 2-3 mL DCM. The crude product was purified by chromatography on silica gel using 7:3 n-hexane and acetone as eluent. Yield: 50 mg, 52%, dark green solid. .sup.1H NMR (500 MHz, CD.sub.2Cl.sub.2): δ 0.83 (d, J=6.5 Hz, 3H), 1.50 (d, J=7.3 Hz, 3H), 1.60 (s, 3H), 2.09 (s, 3H), 2.13 (s, 3H), 2.39 (s, 3H), 2.46 (s, 3H), 2.58 (s, 3H), 2.63 (s, 3H), 3.78 (m, 1H), 3.84 (m, 1H), 3.91 (m, 1H), 4.04 (m, 1H), 4.14 (m, 1H), 6.02 (s, 1H), 6.98 (s, 1H), 7.06 (s, 1H), 7.14 (s, 1H), 7.63 (m, 2H), 8.34 (dd, J=2.2, 8.7 Hz, 1H), 17.18 (s, 1H) ppm. .sup.13C NMR (125 MHz, CD.sub.2Cl.sub.2): δ 18.0, 18.9, 19.9, 20.5, 20.9, 21.3, 21.5, 24.4, 40.5, 51.7, 51.9, 117.3, 122.2, 128.7, 129.1, 130.1, 130.2, 130.7, 131.1, 131.3, 135.8, 137.3, 138.4, 139.8, 140.6, 141.0, 142.7, 149.7, 156.6, 212.4, 280.5 ppm. FAB-MS C.sub.31H.sub.37C.sub.12N.sub.3O.sub.2RuS [M].sup.+ 687.1. found 687.0.

Example 7

Preparation of

(35) ##STR00017##

2-(3-naphtylsulfanyl)benzenecarbaldehyde

(36) This reactant was synthesized according to the literature procedure in Zhang H. Q., Xia Z., Kolasa T., Dinges J. Tetrahedron Letters 2003, 44, 8661-8663.

1-(3-naphtylsulfanyl)-2-vinylbenzene

(37) Methyl triphenylphosphonium iodide (1.56 g, 3.87 mmol) was dissolved in 25 mL ether in a 50 mL round-bottom flask at 0° C. under dry nitrogen. To the mixture was added in one portion potassium tert-butoxide (0.46 g, 4.15 mmol) and was stirred for 10 min at room temperature. 2-(3-naphtylsulfanyl)benzenecarbaldehyde (0.73 g, 2.77 mmol) was added in one portion at 0° C. and the reaction mixture was stirred for additional 2.5 h at room temperature. The mixture was added to 50 mL of saturated sodium bicarbonate solution, and extracted with 3×50 mL portions of ether. The extracts were dried with magnesium sulfate and evaporated. The light yellow oil of the crude product was further purified by chromatography on silica gel using 9:1 petroleum ether 60-80: ether as eluent to afford a colorless oil (0.58 g, 81%). .sup.1H-NMR (500 MHz, CDCl3): δ 5.35 (dd, J=1.3, 11.0 Hz, 1H), 5.77 (dd, J=1.3, 17.5 Hz, 1H), 7.24-7.51 (m, 7H), 7.67-7.81 (m, 5H) ppm. .sup.13C-NMR (125 MHz, CDCl3): δ 116.28, 125.85, 126.20, 126.50, 127.22, 127.48, 127.68, 127.97, 128.24, 128.49, 128.70, 131.91, 132.81, 133.72, 133.78, 133.81, 134.52, 139.71 ppm. EI-MS: m/z M+ Calc. 262.3. found 262.2.

The Compound of Formula 1A Wherein R is Naphthyl (Cis and Trans Isomers)

(38) 1-(3-naphtylsulfanyl)-2-vinylbenzene (36.7 mg, 0.14 mmol), cuprous chloride (16.7 mg, 0.16 mmol) and (1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (119 mg, 0.14 mmol) were dissolved in 6 mL dichloromethane in a 10 mL round-bottom flask under dry nitrogen topped with a reflux condenser. The reaction mixture was refluxed for 5 h. The resulting mixture was evaporated to dryness. The crude product was purified by chromatography on silica gel using 7:3 n-hexane:acetone as eluent to give a green solid (56.0 mg, 55%). Two additional byproducts were separated by chromatography, but only one was fully characterized by NMR analysis: the trans-dichloro isomer as a green solid (8.1 mg, 9%) and an additional green solid (14.2 mg), being probably the six coordinated product with the phosphine ligand still bound. Both byproducts converted with time to the cis isomer according to NMR analysis.

(39) The cis di-chloro isomer: .sup.1H-NMR (500 MHz, CD.sub.2Cl.sub.2): δ 1.75 (s, 3H), 2.18 (s, 3H), 2.26 (s, 3H), 2.49 (s, 3H), 2.61 (s, 3H), 2.74 (s, 3H), 3.88-3.99 (m, 2H), 4.08-4.20 (m, 2H), 6.06 (bs, 1H), 6.73 (dd, J=1.8, 8.7 Hz, 1H), 6.92 (dd, J=1.0, 7.6 Hz, 1H), 6.95 (bs, 1H), 7.03 (m, 2H), 7.14 (d, J=7.7 Hz, 1H), 7.19 (dt, J=0.9, 7.5 Hz, 1H), 7.38 (dt, J=1.2, 7.5 Hz, 1H), 7.49-7.55 (m, 2H), 7.58 (d, J=8.5 Hz, 1H), 7.77-7.80 (m, 2H), 7.83 (d, J=1.8 Hz, 1H), 17.14 (d, J=0.8 Hz, 1H), ppm. .sup.13C-NMR (125 MHz, CD.sub.2Cl.sub.2): δ17.90, 18.94, 20.00, 20.46, 21.25, 21.44, 51.93, 52.06, 123.88, 126.77, 127.20, 127.94, 128.07, 128.26, 128.41, 129.72, 129.95, 129.96, 130.05, 130.32, 130.67, 130.97, 132.39, 133.30, 133.56, 134.00, 135.91, 136.07, 137.04, 138.03, 138.99, 139.25, 140.17, 140.46, 155.49, 214.19, 283.94 ppm. ESI m/z (M-Cl).sup.+: Calculated 691.15. found 690.99. Elemental Analysis: Calculated for a monohydrate: C, 61.28; H, 5.41; N, 3.76. Found C, 61.38; H, 5.38; N, 3.47. NMR analysis supports the presence of a water molecule.

(40) The trans di-chloro isomer: .sup.1H-NMR (500 MHz, CD.sub.2Cl.sub.2): δ 2.40 (s, 6H), 2.45 (s, 12H), 4.10 (s, 4H), 6.73 (dd, J=1.8, 8.6 Hz, 1H), 6.88 (dd, J=0.9, 7.7 Hz, 1H), 7.04 (bs, 4H), 7.27 (dt, J=0.9, 7.7 Hz, 1H), 7.32 (d, J=7.7 Hz, 1H), 7.41-7.47 (m, 2H), 7.50-7.53 (m, 2H), 7.65-6.67 (m, 2H), 7.72 (d, J=7.7 Hz, 1H), 17.34 (d, J=0.6 Hz, 1H).

Example 8

Preparation of

(41) ##STR00018##

1-Bromopyrene

(42) Pyrene (2 g, 9.9 mmol), NBS (1.78 g, 10 mmol) were dissolved in 20 mL of CHCl.sub.3 under dry nitrogen topped with a reflux condenser. The reaction was stirred at 65° C. and monitored by GC-MS until complete. After evaporation of the solvent the crude product was further purified by chromatography on silica gel using 20:1 petroleum ether 60-80: EtOAc as eluent to afford a yellow solid (2 gr, 72%). .sup.1H-NMR (500 MHz, CD2Cl2): δ 8.02-8.11 (m, 4H), 8.17-8.24 (m, 4H), 8.41 (d, J=9.2 Hz, 1H). .sup.13C-NMR (125 MHz, CD.sub.2Cl.sub.2): δ 120.2, 124.4, 125.4, 126.1, 126.2, 126.3, 127.1, 127.6, 128.2, 129.5, 130.0, 130.5, 131.1, 131.2, 131.4, 131.7. EI-MS: m/z M.sup.+ Calculated 280.0. found 280.0.

Pyrene-1-thiol

(43) 1-Bromopyrene (550 mg, 1.96 mmol) and sodium methanethiolate (480 mg, 6.85 mmol) were dissolved in freshly distilled DMF under dry nitrogen. The reaction was stirred at 150° C. and monitored by GC-MS until complete. After completion 50 mL of HCl 0.1M were added to the reaction mixture and extracted with 3 portions of ether. The organic phase was washed with 2 portions of water. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using 5:1 petroleum ether (60-80):EtOAc as eluent to afford a yellow solid (300 mg, 65%). .sup.1H-NMR (500 MHz, toluene-d8, DMSO-d6): δ 7.35 (s, 1H), 8.10-8.37 (m, 8H), 8.67 (d, J=9.2 Hz, LH). .sup.13C-NMR (125 MHz, toluene-d8, DMSO-d6): δ 123.7, 123.8, 124.6, 124.9, 125.7, 125.8, 126.3, 127.0, 127.7, 128.6, 130.1, 130.3, 130.6, 130.8, 131.2, 131.7. EI-MS: m/z M.sup.+ Calculated 234.0. found 234.0.

2-(pyrene-3-ylthio)-benzaldehyde

(44) 2-fluoro-benzaldehyde (477 mg, 3.8 mmol), potassium carbonate (700 mg, 5.0 mmol) and pyrene-1-thiol (300 mg, 1.28 mmol) were dissolved in 15 mL of dry DMF under dry nitrogen, topped with a reflux condenser. The reaction mixture was heated to 130° C. for 24 h. After cooling the mixture was added to 50 mL of saturated potassium carbonate solution, and the mixture was extracted with 3 portions of ether. The extracts were dried with magnesium sulfate and evaporated. The residue of the crude product was further purified by chromatography on silica gel using 10:1 petroleum ether (60-80) and EtOAc as eluent to afford a yellow solid (200 mg, 46%). .sup.1H-NMR (500 MHz, CDCl.sub.3): δ 6.56 (dd, J=0.8, 7.9 Hz, 1H), 7.07-7.22 (m, 2H), 7.89 (dd, J=1.7, 7.2 Hz, 1H), 8.02-8.28 (m, 8H), 8.58 (d, J=9.2 Hz, 1H), 10.45 (s, 1H). .sup.13C-NMR (125 MHz, CDCl.sub.3): δ 124.7, 124.9, 125.3, 125.5, 125.9, 126.0, 126.4, 127.1, 128.0, 128.7, 129.0, 130.8, 131.0, 132.5, 133.3, 133.4, 133.8, 133.9, 137.0, 143.2, 191.6. EI-MS: m/z M.sup.+ Calculated 338.1. found 338.1.

(pyrene-3-yl)-(2-vinylphenyl)sulfane

(45) Methyl triphenylphosphonium iodide (250 mg, 0.62 mmol) was dissolved in 20 mL of dry THF at 0° C. under dry nitrogen. To the mixture was added in one portion potassium tert-butoxide (75 mg, 0.66 mmol) and was stirred for 10 min at room temperature. 2-(pyrene-3-ylthio)-benzaldehyde (150 mg, 0.44 mmol) was added in one portion at 0° C. and the reaction mixture was stirred for additional 5 h at room temperature. The mixture was added to 50 mL of saturated sodium bicarbonate solution, and extracted with 3 portions of ether. The extracts were dried with magnesium sulfate and evaporated. The crude product was further purified by chromatography on silica gel using 20:1 petroleum ether (60-80):EtOAc as eluent to afford a yellow solid (100 mg, 70%). .sup.1H-NMR (500 MHz, CDCl.sub.3): δ 5.36 (dd, J=1.3, 11.3 Hz, 1H), 5.77 (dd, J=1.3, 17.4 Hz, 1H), 6.92 (dd, J=1.3, 7.8 Hz, 1H), 7.02-7.05 (m, 1H), 7.20-7.23 (m, 1H), 7.37 (dd, J=10.8, 17.4 Hz, 1H), 7.61 (dd, J=1.3, 7.8 Hz, 1H), 7.94 (d, J=8.2 Hz, 1H), 8.01-8.22 (m, 8H), 8.61 (d, J=9.5 Hz, 1H). .sup.13C-NMR (125 MHz, CDCl.sub.3): δ 116.4, 124.4, 124.5, 125.2, 125.3, 125.5, 126.1, 126.2, 126.9, 127.2, 127.8, 128.4, 128.5, 128.9, 130.9, 131.0, 131.1, 131.2, 131.4, 134.3, 137.9. EI-MS: m/z M.sup.+ Calculated 336.1. found 336.1.

The Compound of Formula 1A Wherein R is Pyernyl

(46) (pyrene-3-yl)-(2-vinylphenyl)sulfane (50 mg, 0.15 mmol), cuprous chloride (16.0 mg, 0.16 mmol) and (1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (126 mg, 0.15 mmol) were dissolved in 6 mL dichloromethane in a 10 mL round-bottom flask under dry nitrogen topped with a reflux condenser. The reaction mixture was refluxed for 20 h. The resulting mixture was purified by chromatography on silica gel using 7:3 n-hexane:acetone as eluent to give a green solid (80 mg, 67%). .sup.1H-NMR (500 MHz, CD.sub.2Cl.sub.2): δ 2.11 (s, 3H), 2.12 (s, 3H), 2.15 (s, 3H), 2.43 (s, 3H), 2.49 (s, 3H), 2.52 (s, 3H), 3.92-4.24 (m, 4H), 5.98 (s, 1H), 6.64 (s, 3H), 6.85-6.97 (m, 5H), 7.09-7.12 (m, 1H), 7.19-7.21 (m, 1H), 7.32 (d, J=8.8 Hz, 1H), 7.90 (d, J=8.8 Hz, 1H), 8.02 (d, J=8.8 Hz, 1H), 8.12 (m, 1H), 8.21 (d, J=8.8 Hz, 1H), 8.31-8.36 (m, 1H), 8.81 (d, J=8.8 Hz, 1H), 17.26 (s, 1H). .sup.13C-NMR (500 MHz, CD.sub.2Cl.sub.2): δ 17.7, 18.2, 19.6, 19.9, 20.7, 20.8, 51.4, 51.9, 124.4, 125.9, 126.2, 126.4, 127.3, 128.7, 128.9, 129.0, 129.2, 129.3, 129.4, 129.5, 130.2, 130.6, 131.1, 131.9, 133.1, 135.3, 135.6, 136.5, 137.2, 138.6, 139.4, 139.5, 154.5, 213.8, 283.4. ESI m/z (M-Cl).sup.4: Calculated 765.16. found 764.95.

Example 9

The Thermo-Switchable Behavior of the Catalyst of the Invention in Ring Closing Metathesis Reaction

(47) Olefin starting material: diene

(48) Catalyst: The compound of Example 1

(49) Reaction: Ring closing metathesis

(50) A 2 ml toluene solution of 0.1M diethyl diallylmalonate and 1 mol % the compound of Example 1 was stirred in a 10 ml round-bottomed flask under dry nitrogen, topped with a reflux condenser. The reaction was carried out with intermittent periods of heating at 80° C. and cooling to 25° C. The progress of the reaction was determined by GC-MS. [GC-MS parameters: initial temperature 80° C., initial time 2 min., maximum temperature 325° C., rate 30 deg/min, equilibration time 0.5 min., final time 8 min., total time 17.33 min. Mode:split 100:1. Inlet temp. 250° C. Detector temp. 300° C. Retention time for diethyl cyclopent-3-ene-1,1-dicarboxylate 5.28 min. Retention time for diethyl diallylmalonate, 5.54 min. The reaction was monitored after 1 hr, 2 hrs, 3 hrs, 4 hrs, 5 hrs, 6 hrs, 7 hrs, 19 hrs, 21 hrs, 23 hrs, 25 hrs, 27 hrs, 45 hrs, 50 hrs, 53 hrs. The reaction was first heated for 2 hours at 80° C., then cooled to room temperature for 2 hours, then heated to 80° C. for two hours, then cooled to room temperature for 15 hours, then heated for 6 hours at 80° C., then cooled for 18 hours, then heated for 8 hours.].

(51) The conversion of the starting material (%) versus the accumulating reaction time (hours) is plotted in FIG. 1. As shown in the figure, at 25° C. the composition of the reaction mixture remains essentially constant whereas at 80° C. appreciable conversion of the starting material was measured, clearly demonstrating the thermo-switchable behavior of the novel catalyst.

Example 10

The Thermo-Switchable Behavior of the Catalyst of the Invention in Ring-Opening Metathesis Polymerization

(52) Olefin starting material: cyclolalkene

(53) Catalyst: The compound of Example 1

(54) Reaction: Ring opening metathesis polymerization

(55) In a 20 ml vial, the monomer dimethyl 5-nonbornene-2,3-dicarboxylate (1.05 g, 5 mmol) was dissolved in 10 ml toluene together with mesitylene as internal standard (1.10 g, 9.15 mmol). In a second 20 ml vial, the catalyst of Example 1 was placed (10 mg, 0.016 mmol). The monomer solution was transferred to the second vial and the reaction mixture was stirred at 25° C. and 80° C. periodically, such that at each period of time, the reaction mixture was held at the selected temperature for approximately 20 minutes. The progress of the reaction was determined by GC-MS. The conversion of the starting material (%) versus the accumulating reaction time (minutes) is plotted in FIG. 2. As shown in the figure, at 25° C. the composition of the reaction mixture remains essentially constant whereas at 80° C. appreciable conversion of the starting material was measured, clearly demonstrating the thermo-switchable behavior of the novel catalyst.

Example 11

The Thermal Activation of the Catalysts of the Invention in Ring Closing Metathesis Reaction

(56) Olefin starting material: diene

(57) Catalyst: The compounds of Examples 1-5

(58) Reaction: Ring closing metathesis

(59) Thermal activation behavior was tested by stepwise heating a toluene solution of the catalysts in the presence of diethyl diallylmalonate (0.1 M concentration with 1 mol % catalyst). The benchmark ring closing metathesis (RCM) reaction was monitored by GC-MS while quickly raising the temperature by 20° C. every 2 h until a temperature of 100° C. was reached. The results are presented in FIG. 3.

(60) It can be seen from FIG. 3 that the catalysts according to the present invention are essentially inactive at room temperature, and become active by means of heating the reaction mixture to above a threshold temperature. The introduction of bulkier substituents increased the reactivity of the catalyst, such that the threshold temperature for the compounds of Formula IA wherein R is tert-butyl is lower than the corresponding threshold temperature for the compounds wherein R is methyl, ethyl and isopropyl. Among the compounds of the invention, the compound of formula IAc, wherein R is isopropyl, is considered to be especially useful for certain applications, since at room temperature it displays no activity even after two weeks of storage with the olefin, whereas at about 80° C. it accelerates the metathesis reaction effectively.

Example 12

The Light Activation of the Catalysts of the Invention in Ring Closing Metathesis Reaction

(61) Olefin starting material: diene

(62) Catalyst: The compounds of Examples 5, 7 and 8

(63) Reaction: Ring closing metathesis

(64) An NMR tube was charged with 0.6 ml of CD.sub.2Cl.sub.2, the diene starting material (at a concentration of 0.1M) and the catalyst (at a loading of 5% mol). The solution was exposed to UV irradiation (100 W UV lamp at 365 nm) for a period of 5 hours at 28° C. In addition, a similar set of solutions was prepared in order to test the activation induced by visible light (instead of the UV light). Reaction progress was determined by injection to GC-MS after 24 h using mesitylene as an internal standard.

(65) The results for both types of light activation are reported in table 1:

(66) TABLE-US-00001 TABLE 1 Diene starting Yield Entry material Catalyst Product UV VIS a Example 5 0   86% 60% b Example 7   77% 70% c Example 8   62% ND d Example 5   85% 78% e Example 7   78% 89% f Example 5 0 >99% 96% g Example 7   97% 97% h Example 5 >99% 95% i Example 7   94% 95%

(67) (In table 1, Ts indicates a tosyl group). It should be noted that without the light irradiation, the formation of the product was not observed.

Example 13

The Light Activation of the Catalysts of the Invention in Ring Closing Metathesis Reaction: The Correlation Between the Trans-Cis Ratio and the Conversion of the Starting Material

(68) The ring closing metathesis reaction of diethyl diallylmalonate (DDM) was carried out in the presence of the catalysts of Examples 5 and 7 as described before. Several solutions were prepared, and each was of the solutions was irradiated by UV light (365 nm) for a different period of time. The cis-dichloro.fwdarw.trans-dichloro isomerization which occurred in each solution was quantified (the ratio between the two isomers was measured by .sup.1H-NMR). In addition, the degree of the conversion of the DDM starting material for each solution was measured by GC-MS (the measurements were taken 24 hours after the addition of the DDM starting material to the solution). The results are shown in Table 2.

(69) TABLE-US-00002 TABLE 2 The ratio between the cis and Conversion UV irradiation trans isomers of DDM, % time (hours) Example 5 Example 7 Example 5 Example 7 0 100:0  100:0 0 0 0.5 47:1 157:1 21 6 1 10:1  60:1 39 13 5  3:1  5.5:1 85 74 10 2.6:1   6:1 86 65

(70) The results reported in Table 2 illustrate that the higher the amount of the trans isomer in the reaction mixture, the greater is the degree of conversion of the starting material. The correlation found between the amount of the trans isomer generated in the reaction mixture following the UV irradiation, and the conversion of the starting material, allows the practitioner to suitably adjust the time period of the irradiation in order to maximize the amount of the trans isomer, and hence the degree of conversion of the starting material.

Example 14

The Light Activation of the Catalysts of the Invention in Ring-Opening Metathesis Polymerization

(71) Olefin starting material: cyclolalkene monomer

(72) Catalyst: The compounds of Example 5 and 7

(73) Reaction: Ring opening metathesis polymerization

(74) A 10 mm NMR tube with a magnetic stirrer was charged with 2 mL of CH.sub.2Cl.sub.2, the monomer (1 mmol), the catalyst (3.33 μmol, 0.3% loading), and mesitylene as an internal standard (200 mg). The solution was irradiated by UV light (100 W UV lamp at 365 nm) at 28° C. for 5 h period. The resulting mixture was stirred for 24 h. Reaction progress was determined by injection to GC-MS after 24 h. The polymer product is isolated by pouring a sample from the reaction mixture in ether, filtering, and washing the white gum with ether (all color is removed by washing), followed by 12 hour-drying under high vacuum. The resulting polymer was characterized by GPC and NMR analyses.

(75) The monomers which were polymerized, and the degree of conversion are represented in table 3 (conversions were calculated by the reduction in monomer concentration as determined by CG-MS):

(76) TABLE-US-00003 TABLE 3 Conversion of Entry Monomer Catalyst the monomer a 5-nonbornene-2,3- Example 5 40% dicarboxylate b 5-nonbornene-2,3- Example 7 66% dicarboxylate c Cyclooctene Example 5 96% d Cyclooctene Example 7 >99% e 1,5-cyclooctadiene Example 5 86% f 1,5-cyclooctadiene Example 7 84%

Example 15

Controlling the Progress of a Ring Closing Metathesis Reaction

(77) An NMR tube was charged with 0.6 ml of C.sub.2D.sub.2Cl.sub.4, the starting material diethyl diallylmalonate (at a concentration of 0.1M) and the catalyst of Example 7 (at a loading of 5 mol %). The solution was irradiated at 28° C. for 15 minutes (100 W UV lamp at 365 nm), followed by 5 minutes heating to 80° C. The conversion of the starting material, which was measured after 24 hours at room temperature, was about 15%. It has been found that the 5 minutes heating period allows an essentially complete transformation of the trans isomer present in the reaction mixture into the cis isomer, and hence the termination of the reaction. Thus, when the reaction mixture is periodically subjected to light irradiation (15 minutes) and subsequent heating (5 minutes at 800), with an intermission of four hours at room temperature between each irradiation-heating cycle, then the reaction has the profile illustrated in FIG. 4 (where the “activate” corresponds to the irradiation-heating cycle, and the “rest” to the intermission period).