ADDUCT COMPRISING AT LEAST A TRANSITION METAL AND AN ADDUCT OF A CARBON ALLOTROP AND A PYRROLIC COMPOUND

Abstract

The present invention relates to an adduct comprising at least one transition metal and an adduct between a sp.sup.2 carbon allotrope and a pyrrole compound. In particular, the invention relates to an adduct comprising at least one transition metal and hydrophylic adducts between a sp.sup.2 carbon allotrope and a pyrrole compound. Such adduct is preferentially used as catalytic system in a chemical reaction such as C—H activation, in particular the Hydrogen Isotope Exchange with isotopes such as deuterium and tritium.

Claims

1. An adduct of a transition metal selected from the group consisting of: iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, chromium, molybdenum, niobium, rhenium, tantalum, zirconium, or mixture thereof; with an adduct of: a sp.sup.2 carbon allotrope and/or its derivative and compound of formula (I) ##STR00003## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 are independently selected from the group consisting of: hydrogen, alkyl C.sub.1-C.sub.3, alkenyl or alkynyl C.sub.2-C.sub.6 linear or branched, aryl, alkyl-aryl C.sub.1-C.sub.6 linear or branched, alkenyl-aryl C.sub.2-C.sub.6 linear or branched, alkynyl-aryl C.sub.2-C.sub.6 linear or branched, and heteroaryl, and Y, Z, and W are independently selected from the group consisting of hydrogen, alkyl C.sub.1-C.sub.6, and alkenyl or alkynyl C.sub.2-C.sub.6 linear or branched, or selected from the group consisting of: ##STR00004## wherein R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12, R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17, R.sub.18, R.sub.19, R.sub.20, R.sub.21, R.sub.22, R.sub.23, R.sub.24, are independently selected from the group consisting of hydrogen, alkyl C.sub.1-C.sub.6, alkenyl or alkynyl C.sub.2-C.sub.6 linear or branched, aryl, alkyl-aryl C.sub.1-C.sub.6 linear or branched, alkenyl-aryl C.sub.2-C.sub.6 linear or branched, alkenyl-aryl C.sub.2-C.sub.6 linear or branched, heteroaryl, and carboxyl, and wherein b is an integer from 1 to 4 and a, c, d and e are, independently, integers from 1 to 12.

2. The adduct according to claim 1, wherein the transition metal is selected from the group consisting of: nickel, ruthenium, rhodium, palladium, iridium, platinum and mixtures thereof.

3. The adduct according to claim 1, wherein the R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are independently selected from the group consisting of: H, CH.sub.3, CH.sub.2CH.sub.3, CH.sub.2CH.sub.2CH.sub.3, and phenyl.

4. The adduct according to claim 1, wherein the carbon allotrope or its derivative is selected from the group consisting of: carbon black, fullerene, Buchminstefullerenes, carbon nanohorns, carbon nanotubes, single-walled or multi-walled, carbon nanobuds, graphene, bilayer graphene, few-layer graphene, graphenylene, ciclocarbons, and graphites with a number of stacked graphene layers from 2 to 10000.

5. The adduct according to claim 1, wherein the carbon allotrope derivative contains functional groups selected from the group consisting of: functional groups containing oxygen, hydroxyls, epoxies; functional groups containing carbonyls, aldehydes, ketones, carboxylic acids; functional groups containing nitrogen atoms, amines, amides, nitriles, diazonium salts, imines; functional groups containing sulfur atoms, sulfides, disulfides, sulfinates, sulfoxides, mercaptans, sulfones, sulfinic, sulfoxylic, and sulfonic groups.

6. The adduct according to claim 1, wherein the derivative of said carbon allotrope is graphite oxide.

7. The adduct according to claim 1, wherein the derivative of said carbon allotrope is graphene oxide.

8. A process for the preparation of an adduct according to claim 1, comprising the steps of: i. providing a solution and/or suspension of a compound of formula (I) in a protic or aprotic polar solvent; ii. providing a mixture of the carbon allotrope in a protic or aprotic polar solvent used for the preparation of the solution and/or suspension referred to in step i.; iii. mixing said solution and/or suspension (i) and said mixture (ii); iv. stirring; v. if necessary, removing said solvent from the obtained mixture; vi. providing energy; vii. if necessary, dispersing the obtained mixture in the protic or aprotic polar solvent; viii. adding a salt of the transition metal soluble in the selected protic or aprotic polar solvent; ix. stirring; x. if necessary, removing said solvent from the obtained mixture.

9. The process according to claim 8, further comprising: xi. if necessary, dispersing the mixture obtained after step vi in the protic or aprotic polar solvent; xii. adding a reducing agent; xiii. stirring; xiv. removing said solvent from the obtained mixture.

10. The process according to claim 9, wherein the reducing agent is selected from the group consisting of: alcohols, aldehydes, carboxylic acids.

11. The process according to claim 9, wherein the reducing agent is present in an equimolar amount with respect to the transition metal salts.

Description

[0091] Characteristics and advantages of the invention will be more apparent from the description of preferred embodiments, shown by way of non-limiting example in the accompanying drawings, wherein:

[0092] FIG. 1 shows the .sup.1H NMR spectra (400 MhZ, CDCl.sub.3) for the deuteration of quinoline by using: (a) catalyst and reaction conditions as reported in example 19 (invention); (b) commercial ruthenium on carbon catalyst (RU/C); .sup.1H NMR spectrum of pure chinolin is also reported (c).

EXAMPLES

Materials

[0093] Reagents and solvents are commercially available and were used without any further purification: Serinol and isoserinol were kindly provided by Bracco. 2,5-hexandione, oxalyc acid, Ruthenium(III) chloride trihydrate, 1,2-propandiol, Ruthenium on carbon (Ru/C), quinoline and THF were purchased from Sigma-Aldrich.

[0094] Carbon Black N326 (CBN326) and N234 (CBN234) were from Cabot. Multiwall Carbon Nanotubes were NANOCYL® NC7000™ series, with carbon purity of 90%, average length of about 1.5 μm, BET surface area of 275 m.sup.2/g, 316 ml of absorbed DBP/100 grams of CNT. High surface area graphite (HSAG) was Nano24 from Asbury Graphite Mills Inc., with carbon content reported in the technical data sheet of at least 99 wt %. Chemical composition determined from elemental analysis was, as wt %: carbon 99.5, hydrogen 0.4, nitrogen 0.1, oxygen <0.05. BET surface area was 330 m.sup.2/g and DBP absorption was 162 mL/100 g.

[0095] Graphene Nanoplatelet (GnP) were from Sigma Aldrich.

[0096] In the following, are the examples on the preparation of adducts of sp.sup.2 carbon allotropes (CA).

[0097] Examples 1-6 describe the preparation of adducts between sp.sup.2 carbon allotropes and pyrrole compounds (PyC). They are named CA-PyC

[0098] Examples 7-12 describe the preparation of adducts between the adducts of sp.sup.2 carbon allotropes with pyrrole compounds (CA-PyC) and Rutenium (Ru). These adducts are named CA-PyC/Ru. In these examples, methanol was used as solvent.

[0099] Examples 13-18 describe as well the preparation of adducts between the adducts of sp.sup.2 carbon allotropes with pyrrole compounds (CA-PyC) and Rutenium (Ru). These adducts are named CA-PyC/Ru. In these examples 1,2-propandiol was used as solvent.

[0100] Examples 19-20 demonstrate the selectivity as catalyst of the adduct CA-PyC/Metal of the present invention. In particular, Example 19 demonstrates the selectivity as catalyst of the adduct CA-PyC/Ru as catalysts for the deuteration of quinolone. In Example 19, the CA-PyC/Ru adduct prepared in Example 7 was used. Example 20 demonstrates the reusability of the catalyst.

[0101] Example 21 is a comparative example. a commercial ruthenium on carbon catalyst (RU/C) was used.

Examples 1-6: Preparation of Adducts Between Pyrrole Compounds (PyC) and Sp.SUP.2 .Hybridized Carbon Allotropes (CA): CA-PyC

Example 1: Adduct Between Multi-Walled Carbon Nanotubes (CNT) and 2-(2,5-dimethyl-1H-pyrrol-1-yl)propan-1,3-diol (SP)-CNT-SP

[0102] In a 50 mL flask, equipped with magnetic stirrer, CNT (200 mg, 2.8 mmol) and acetone (15 mL) were sequentially added. The thus obtained suspension was sonicated for 15 minutes using a 2 L ultrasound water bath. Afterwards, a solution of 2-(2,5-dimethyl-1H-pyrrol-1-yl)propan-1,3-diol (10% mol/mol, 0.28 mmol) in acetone (25 mL) is added to the suspension.

[0103] The mixture was then sonicated for 15 minutes. Afterwards, the acetone was removed under reduced pressure using a rotavapor. The black powder thus obtained was placed in a 100 mL flask and heated to 180° C. for 2 h. The adduct was then transferred in a Buchner filter and repeatedly washed with acetone (3×100 mL).

Example 2: Adduct Between Graphene Nanoplatelets (GnP) and 2-(2,5-dimethyl-1H-pyrrol-1-yl)propan-1,3-diol (SP)-GnP-SP

[0104] GnP-SP was prepared with the procedure described in example 1, using graphene nanoplatelets instead of CNT.

Example 3: Adduct Between High Surface Area Graphite (HSAG) and 2-(2,5-dimethyl-1H-pyrrol-1-yl)propan-1,3-diol (SP)-HSAG-SP

[0105] HSAG-SP was prepared with the procedure described in example 1, using high surface area graphite instead of CNT.

Example 4: Adduct Between Carbon Black (CBN326) and 2-(2,5-dimethyl-1H-pyrrol-1-yl)propan-1,3-diol (SP)-CBN326-SP

[0106] CBN326-SP was prepared with the procedure described in example 1, using carbon black CBN326 instead of CNT.

Example 5: Adduct Between Carbon Black (CBN234) and 2-(2,5-dimethyl-1H-pyrrol-1-yl)propan-1,3-diol (SP)-CBN234-SP

[0107] CBN234-SP was prepared with the procedure described in example 1, using carbon black CBN234 instead of CNT.

Example 6: Adduct Between High Surface Area Graphite (HSAG) and 3-(2,5-dimethyl-1H-pyrrol-1-yl)propan-1,2-diol (iSP)-HSAG-iSP

[0108] HSAG-iSP was prepared with the procedure described in example 1, using 3-(2,5-dimethyl-1H-pyrrol-1-yl)propan-1,2-diol instead of SP.

Examples 7-12: Preparation of Adducts Between Pyrrole Functionalized Carbon Allotropes (CA-PyC) and Rutenium (Ru) by Using Methanol as Solvent: CA-PyC/Ru

Example 7: Preparation of the Adduct Between CNT-SP and Rutenium (CNT-SP/Ru)

[0109] In a 100 mL flask, equipped with magnetic stirrer, CNT-SP (200 mg) and methanol (50 mL) were sequentially added. The thus obtained suspension was sonicated for 10 minutes using a 2 L ultrasound water bath. Afterwards, Ruthenium(III) chloride trihydrate (10% mol/mol) and oxalic acid were added in sequence to the suspension. The mixture was then sonicated for 10 minutes. The so obtained mixture was heated for 3 hours at 70° C. Afterwards, the mixture was centrifugated at 4000 rpm for 30 minutes (3×10 mL methanol). The supernatant was removed and the black powder was dried.

Example 8: Preparation of the Adduct Between GnP-SP and Rutenium (GnP-SP/Ru)

[0110] GnP-SP/Ru was prepared with the procedure described in example 7, using GNP-SP instead of CNT-SP.

Example 9: Preparation of the Adduct Between HSAG-SP and Rutenium (HSAG-SP/Ru)

[0111] HSAG-SP/Ru was prepared with the procedure described in example 7, using HSAG-SP instead of CNT-SP.

Example 10: Preparation of the Adduct Between CBN326-SP and Rutenium (CBN326-SP/Ru)

[0112] CBN326-SP/Ru was prepared with the procedure described in example 7, using CBN326-SP instead of CNT-SP.

Example 11: Preparation of the Adduct Between CBN234-SP and Rutenium (CBN234-SP/Ru)

[0113] CBN234-SP/Ru was prepared with the procedure described in example 7, using carbon black CBN234-SP instead of CNT-SP.

Example 12: Preparation of the Adduct Between HSAG-iSP and Rutenium (HSAG-iSP/Ru)

[0114] HSAG-iSP/Ru was prepared with the procedure described in example 7, using HSAG-iSP instead of CNT-SP.

Examples 13-18: Preparation of Adducts Between Pyrrole Functionalized Carbon Allotropes (CA-PyC) and Rutenium (Ru) by Using 1,2-Propandiol as Solvent: CA-PyC/Ru

Example 13: Preparation of the Adduct Between CNT-SP and Rutenium (CNT-SP/Ru)

[0115] CNT-SP/Ru was prepared with the procedure described in example 7, using 1,2-propandiol instead of methanol as solvent.

Example 14: Preparation of the Adduct Between GnP-SP and Rutenium (GnP-SP/Ru)

[0116] GnP-SP/Ru was prepared with the procedure described in example 7, using 1,2-propandiol instead of methanol as solvent and GnP-SP instead of CNT-SP.

Example 15: Preparation of the Adduct Between HSAG-SP and Rutenium (HSAG-SP/Ru)

[0117] HSAG-SP/Ru was prepared with the procedure described in example 7, using 1,2-propandiol instead of methanol as solvent and HSAG-SP instead of CNT-SP.

Example 16: Preparation of the Adduct Between CBN326-SP and Rutenium (CBN326-SP/Ru)

[0118] CBN326-SP/Ru was prepared with the procedure described in example 7, using 1,2-propandiol instead of methanol as solvent and CBN326-SP instead of CNT-SP.

Example 17: Preparation of the Adduct Between CBN234-SP and Rutenium (CBN234-SP/Ru)

[0119] CBN234-SP/Ru was prepared with the procedure described in example 7, using 1,2-propandiol instead of methanol as solvent and CBN234-SP instead of CNT-SP.

Example 18: Preparation of the Adduct Between HSAG-iSP and Rutenium (HSAG-iSP/Ru)

[0120] HSAG-iSP/Ru was prepared with the procedure described in example 7, using 1,2-propandiol instead of methanol as solvent and HSAG-iSP instead of CNT-SP.

Examples 19-20: Selective Deuteration of Quinoline by Using CA-PyC/Ru as Catalyst

Example 19: Selective Deuteration of Quinoline by Using CNT-SP/Ru as Catalyst

[0121] A Fisher Porter bottle (V=80 mL) is charged with 20 mg of CNT-SP/Ru, prepared as reported in example 7 (0.2 mol %) and placed under vacuum for 5 minutes. A solution of 0.2 mmol of quinoline in dry THF (0.1 M) is added onto the vessel under an Argon flow. The reaction medium is, thus, evacuated from the Argon gas and exposed to 3 cycles of D.sub.2 (1 bar)—Vacuum of 10 minutes each. Then the Fisher Porter bottle is closed and the medium is left to stir for 24 hours at room temperature. Thereafter the Fisher Porter is opened and the gas phase evacuated, the mixture is dissolved in 10 additional mL of distilled THF and it is centrifugated 8000 rpm for 10 minutes in order to separate the catalyst from the organic medium. The selective deuteration of quinoline was evaluated by means of .sup.1H-NMR spectroscopy (FIG. 1a).

Example 20: Selective Deuteration of Quinoline by Using the CNT-SP/Ru Catalyst Used in Example 19 (Reusability of Catalyst)

[0122] A Fisher Porter bottle (V=80 mL) is charged with 20 mg of CNT-SP/Ru, recovered from reaction mixture of example 19, (0.2 mol %) and placed under vacuum for 5 minutes. A solution of 0.2 mmol of quinoline in dry THF (0.1 M) is added onto the vessel under an Argon flow. The reaction medium is, thus, evacuated from the Argon gas and exposed to 3 cycles of D.sub.2 (1 bar)—Vacuum of 10 minutes each. Then the Fisher Porter bottle is closed and the medium is left to stir for 24 hours at room temperature. Thereafter the Fisher Porter is opened and the gas phase evacuated, the mixture is dissolved in 10 additional mL of distilled THF and it is centrifugated 8000 rpm for 10 minutes in order to separate the catalyst from the organic medium. The selective deuteration of quinoline was evaluated by means of .sup.1H-NMR spectroscopy.

Example 21 (Comparative): Deuteration of Quinoline by Using a Commercial Ruthenium on carbon catalyst (RU/C)

Example 21

[0123] A Fisher Porter bottle (V=80 mL) is charged with 20 mg of Ru/C (Aldrich) (0.2 mol %) and placed under vacuum for 5 minutes. A solution of 0.2 mmol of quinoline in dry THF (0.1 M) is added onto the vessel under an Argon flow. The reaction medium is, thus, evacuated from the Argon gas and exposed to 3 cycles of D.sub.2 (1 bar)—Vacuum of 10 minutes each. Then the Fisher Porter bottle is closed and the medium is left to stir for 24 hours at room temperature. Thereafter the Fisher Porter is opened and the gas phase evacuated, the mixture is dissolved in 10 additional mL of distilled THF and it is centrifugated 8000 rpm for 10 minutes in order to separate the catalyst from the organic medium. (FIG. 1b)