One step process for regioselective synthesis of α-acyloxy carbonyls

Abstract

A regioselective N-Heterocyclic Carbene (NHC) catalyzed one step process for high yield synthesis of α-acyloxy carbonyl compounds is disclosed. ##STR00001##

Claims

1. A single-step, one pot process for the preparation of an α-acyloxy carbonyl compound of general formula (I); ##STR00031## wherein R is selected from H, alkyl, aryl, Bn; R.sup.1 is selected from H, alkyl, substituted aryl, unsubstituted aryl, —CH.sub.2OTBS (TBS=Tertiary butyl silyl), —CH.sub.2OBn, —OR, OMOM (Methoxy methelene); Ar is selected from unsubstituted/substituted phenyl group or pyridine group; R and R.sup.1 optionally can combine to form a ring structure containing 3 to 6 carbon atoms and may optionally contain a heteroatom; comprising the steps of: reacting alkene of formula (II) with an aldehyde of formula (III) ##STR00032## in the presence of a N-Heterocyclic carbene catalyst (NHC) selected from ##STR00033## wherein for IVb, Ar=2,4,6-(CH.sub.3).sub.3C.sub.6H.sub.2; for IVc, Ar=2,6-iPr.sub.2C.sub.6H.sub.3, a halogen source, tri-ethyl amine and a solvent in oxygen atmosphere at a temperature in the range of 15-30° C. by stirring for a period in the range of 10-50 hours to obtain a compound of general formula (I); wherein R is selected from H, alkyl, aryl, Bn; R.sup.1 is selected from H, alkyl, substituted aryl, unsubstituted aryl —CH.sub.2OTBS (TBS=Tertiary butyl silyl), —CH.sub.2OBn, —OR, OMOM (Methoxy methelene); Ar is selected from unsubstituted/substituted phenyl group or pyridine group.

2. The process as claimed in claim 1, wherein N-Heterocyclic carbene catalyst is Iva[-IVf, preferably Iva.] ##STR00034##

3. The process as claimed in claim 1, wherein halogen source is selected from the group consisting of N-bromo succinamide (NBS), N-iodo succinamide NIS or N-chloro succinamide NCS.

4. The process as claimed in claim 1, wherein solvent used is di-methyl sulfoxide (DMSO).

5. The process as claimed in claim 1, wherein the N-Heterocyclic carbene catalyst is IVa and the yield of the compound of general formula (I) is in the range of 70 to 92%.

6. The process according to claim 1, wherein representative compound of general formula (I) are: 2-Oxo-2-phenylethyl 4-nitrobenzoate (1a); 2-(4-Methylphenyl)-2-oxoethyl 4-nitrobenzoate (1b); 2-(4-Bromophenyl)-2-oxoethyl 4-nitrobenzoate (Ic); 2-(4-Fluorophenyl)-2-oxoethyl 4-nitrobenzoate (Id); 2-(4-Acetoxyphenyl)-2-oxoethyl 4-nitrobenzoate (Ie); 2-(3,4 Dimethoxyphenyl)-2-oxoethyl 4-nitrobenzoate (If); 1-Oxo-2,3-dihydro-1H-inden-2-yl 4-nitrobenzoate (Ig); 2-Oxo-1,2-diphenylethyl 4-nitrobenzoate (Ih); 1-Oxo-1-phenylpropan-2-yl 4-nitrobenzoate (Ii); 2-((Tert-butyldimethylsilyl)oxy)-1-oxo-1-phenylpropan-2-yl 4-nitro benzoate (Ij); 3-(Benzyloxy)-2-oxopropyl 4-nitrobenzoate (Ik); 3-Oxooctyl 4-nitrobenzoate (II); 2-Oxodecyl 4-nitrobenzoate (Im); 2-Oxo-4-phenylbutyl 4-nitrobenzoate (In); 2-Ethoxy-2-oxoethyl 4-nitrobenzoate (Io); 2-Oxotetrahydro-2H-pyran-3-yl 4-nitrobenzoate (Ip); 2-(Methoxy)-2-oxo-1-phenylethyl 4-nitrobenzoate (Iq); 2-Oxo-2-phenylethyl benzoate (Ir); 2-Oxo-2-phenylethyl 3-methylbenzoate (Is); 2-Oxo-2-phenylethyl 4-bromobenzoate (It); 2-Oxo-2-phenylethyl 4-chIorobenzoate (Iu); 2-Oxo-2-phenylethyl nicotinate (Iv).

7. The process as claimed in claim 1, wherein halogen source is N-bromo succinamide (NBS).

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) Present invention provides a one step, one pot process for the synthesis of α-acyloxy carbonyl compounds with regio selectivity, wherein the starting material is an alkene.

(2) The process leads to novel α-acyloxy carbonyl compounds that may be used as key structural motif for synthesis of useful, therapeutically active compounds.

(3) The present invention provides a single-step, one pot process for the preparation of α-acyloxy carbonyl compounds of general formula (I)

(4) ##STR00006##
General Formula I
wherein
R=H, alkyl, aryl or Bn; R.sup.1═H, alkyl, aryl, —CH.sub.2OTBS, —CH.sub.2OBn, —OR or OMOM;
Ar=aromatic or heteroaromatic;
comprising reacting alkene of formula (II), with an aldehyde of formula (III)

(5) ##STR00007##
wherein, R, R1, Ar are as defined above;
in the presence of a NHC catalyst, a halogen source, triethyl amine and a solvent selected from di-methyl sulfoxide (DMSO) in air at temperature 15-30° C. by stirring for 10-50 hours and isolating compounds of general formula (I) with >70% yields.
N-Heterocyclic carbene catalyst is selected from:

(6) ##STR00008##
wherein, Vb is Ar=2,4,6-(CH.sub.3).sub.3C.sub.6H.sub.2; Vc is Ar=2,6-iPr.sub.2C.sub.6H.sub.3.

(7) Halogen source is selected from N-bromo succinamide (NBS), N-iodo succinamide (NIS) or N-chloro succinamide (NCS) and preferably NBS.

(8) The above process for the preparation of α-acyloxy carbonyl compounds of formula (I), using IVa as NHC— catalyst is depicted below in FIG. 1.

(9) The present invention provides a process with variations of the NHC catalyst IVa-IVf yielding the corresponding α-acyloxy carbonyl starting from styrene and —NO.sub.2-benzaldehyde as shown in Table 1.

(10) TABLE-US-00001 TABLE 1 NHC catalyzed oxidative functionalization of styrene with 4-NO.sub.2-benzaldehyde: Optimization studies Yield (%).sup.b Entry NHC catalyst Base Solvent of Ia 1 IVa Et.sub.3N DMSO 92 (81).sup.c (46).sup.d 2 IVb Et.sub.3N DMSO 65 3 IVc Et.sub.3N DMSO 47 4 IVd Et.sub.3N DMSO 52 5 IVe Et.sub.3N DMSO 14 6 IVf Et.sub.3N DMSO  8 7 IVa NaH DMSO 54 8 IVa DBU DMSO 52 9 IVa Cs.sub.2CO.sub.3 DMSO 24 10 IVa KOBu.sup.t DMSO 16 11 IVa Et.sub.3N DMSO (5 eq) + THF 15 .sup.aReaction conditions: styrene (5 mmol), p-nitrobenzaldehyde (6 mmol), NHC precatalyst (Va-f) (10 mol %), Base (6 mmol), NBS (5 mmol); all under O.sub.2 atmosphere in DMSO, 25° C., 18 h; .sup.bisolated yield after column chromatographic purification; .sup.cNIS is used instead of NBS; .sup.dNCS is used us halogen source.

(11) The present invention provides a process for the preparation of α-acyloxy carbonyl compounds of formula (II), wherein the NHC catalysts is preferably IVa to IVd with yields greater than 50%.

(12) The present invention provides a process with options of aldehydes to provide α-acyloxy carbonyl with high regioselectivity yield greater than 70% as shown in Table 2.

(13) TABLE-US-00002 TABLE 2 NHC catalyzed oxidative functionalization of styrene with aromatic aldehydes.sup.a Time Products Yield (%).sup.b Entry Aldehydes (IIIa-e) (h) (Ir-v) of (Ir-v) 1 benzaldehyde (IIIa) 38 Ir 68 2 m-tolualdehyde (IIIb) 28 Is 81 3 4-Br-benzaldehyde (IIIc) 22 It 78 4 4-Cl-benzaldehyde (IIId) 24 Iu 75 5 3-pyridine carboxaldehyde (IIIe) 22 Iv 73 .sup.aReaction conditions: styrene (5 m .Math. mol), aromaticaldehyde (5.5 mmol), NHC precatalyst Va (10 mol %), Et.sub.3N (5.5 mmol), NBS (5 mmol) in DMSO under O.sub.2 atmosphere; 25° C.; .sup.bisolated yield after column chromatographic purification.

(14) The present invention provides various α-acyloxy carbonyls synthesized by varying the alkenes (III), with >70% yield as shown in Table 3.

(15) TABLE-US-00003 TABLE 3 NHC catalyzed oxidative functionalization of alkenes with 4-NO.sub.2-benzaldehyde.sup.a time products entry alkenes (IIa-q) (h) (Ia-q) yield (%).sup.b 1 styrene (IIa) 18 Ia 92 2 4-CH.sub.3-styrene (IIb) 20 Ib 77 3 4-Br-styrene (IIc) 18 Ic 71 4 4-F-styrene (IId) 22 Id 79 5 4-OAc-styrene (IIe) 23 Ie 82 6 3,4-(OMe).sub.2 styrene (IIf) 26 If 74 7 indene (IIg) 18 Ii 72 8 stilbene (IIh) 24 Ij 81 9 Ph—CH═CH—CH.sub.2—OTBS (IIi) 28 Ig 92 10 3,4-(O—CH.sub.2—O)—Ph—CH═CH—CH.sub.2—OTBS (IIj) 26 Ih 81 11 benzyloxy 1-propene (IIk) 27 Ik 79 12 1-octene (IIl) 32 Il 71 13 1-decene (IIm) 29 Im 76 14 4-phenyl-1-butene (IIn) 26 In 74 15 ethoxyethene (IIo) 30 Io  78.sup.c 16 dihydropyran (IIp) 28 Ip 69 17 Ph—CH.sub.2—CH═CH—OCH.sub.2OCH.sub.3 (IIq) 32 Iq 73 .sup.aReaction conditions: alkene (5 mmol), p-nitrobenzaldehyde (5.5 mmol), NHC precatalyst IVa (10 mol %), Et.sub.3N (5.5 mmol), NBS (5 mmol) in DMSO under O.sub.2 atmosphere; 25° C.; .sup.bisolated yield after column chromatographic purification; .sup.creaction was carried out at 0° C.

EXAMPLES

(16) Following examples are given by way of illustration therefore should not be construed to limit the scope of the invention.

Example 1

General Experimental Procedure

(17) To a solution of alkenes (IIIa-q) (1 equiv.) in DMSO (20 ml), N-Heterocyclic carbene (10 mol %), N-Bromo succinamide (1 equiv.), triethyl amine (1.2 equiv.) and aldehyde (IVa-f) were added under oxygen atmosphere. The reaction mixture was then stirred at 25° C. After completion (monitored by TLC), the reaction mixture was then concentrated, followed by the addition of H.sub.2O (50 mL). It was extracted with EtOAc (3×50 ml) and the combined organic layers dried over anhydrous Na.sub.2SO.sub.4. Removal of solvent gave α-acyloxy carbonyls (Ia-v), which were purified by column chromatography over silica gel using pet ether/EtOAc (1/19) as eluent to obtain pure α-acyloxy carbonyls in high purity.

Example 2

2-Oxo-2-phenylethyl 4-nitrobenzoate (IIa)

(18) ##STR00009##

(19) Yield: 92%, colorless solid, Mp: 123-124° C.; IR (Nujol, cm.sup.−1): 719, 1104, 1229, 1294, 1376, 1462, 1524, 1598, 1696, 1727, 275, 2840, 2923; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 5.64 (s, 2H), 7.51-7.55 (m, 2H), 7.63-7.65 (m, 1H), 7.97 (d, J=8.5 Hz, 211), 8.33 (s, 4H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 66.9, 123.4, 127.7, 128.9, 130.9, 133.8, 134.0, 134.7, 150.6, 164.0, 191.0: HRMS (ESI): [M+H].sup.+ calcd for C.sub.15H.sub.11NO.sub.5+H: 286.0715. found: 286.0726.

2-(4-Methylphenyl)-2-oxoethyl 4-nitrobenzoate (IIb)

(20) ##STR00010##

(21) Yield: 77%, colorless solid, Mp: 114-115° C.; IR (Nujol, cm.sup.−1): 713, 1135, 1231, 1289, 1374, 1459, 1525, 1604, 1692, 1725, 2840, 2923; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 2.46 (s, 3H), 5.62 (s, 2H), 7.32 (d, J=8.1 Hz, 2H), 7.87 (d, J=8.1 Hz, 2H), 8.33 (s, 4H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 21.8, 66.9, 123.5, 127.8, 129.6, 131.1, 131.5, 134.8, 145.1, 150.7, 164.1, 190.6; HRMS (ESI): [M+H].sup.+ calcd for: C.sub.16H.sub.13NO.sub.5+H: 300.0872. found: 300.0881.

2-(4-Bromophenyl)-2-oxoethyl 4-nitrobenzoate (IIc)

(22) ##STR00011##

(23) Yield: 71%, colorless solid, Mp: 117-118° C.; IR (CHCl.sub.3, cm.sup.−1): 717, 967, 1106, 1124, 1346, 1521, 1701, 1723, 2850, 2920; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 5.58 (s, 2H), 7.67 (m, J=8.5 Hz, 2H), 7.83 (m, J 8.5 Hz, 2H), 8.32 (s, 4H); .sup.13C NMR (100 MHz, CDCl.sub.3): δ 66.7, 123.6, 129.2, 129.5, 131.1, 132.4, 132.6, 134.6, 150.8, 164.0, 190.0; HRMS (ESI): [M+H].sup.+ calcd for C.sub.15H.sub.10BrNNaO.sub.5+H: 363.9820. found: 363.9834.

2-(4-Fluorophenyl)-2-oxoethyl 4-nitrobenzoate (IId)

(24) ##STR00012##

(25) Yield: 79%, colorless solid, Mp: 117-118° C.; IR (CHCl.sub.3, cm.sup.−1): 717, 871, 1131, 1155, 1231, 1320, 1521, 1595, 1698, 1722, 1746; .sup.1H NMR (400 MHz, CDCl.sub.3): δ 5.59 (s, 2H), 7.21 (t, J=8.6 Hz, 2H), 8.01 (dd, J=8.6, J=5.0 Hz, 2H), 8.32 (d, J=2.7 Hz, 4H); .sup.13C NMR (100 MHz, CDCl.sub.3): δ 66.7, 116.1, 116.4, 130.5, 130.5, 131.1, 134.6, 150.8, 164.0, 165.0, 167.5, 189.3; HRMS (ESI): [M+H].sup.+ calcd for C.sub.15H.sub.10FNO.sub.5+H: 304.0621. found: 304.0627.

2-(4-Acetoxyphenyl)-2-oxoethyl 4-nitrobenzoate (IIe)

(26) ##STR00013##

(27) Yield: 82%, colorless solid, Mp: 128-129° C.; IR (Nujol, cm.sup.−1): 716, 1166, 1212, 1294, 1374, 1459, 1525, 1596, 1690, 1717, 1753, 2846, 2917; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 2.35 (s, 3H), 5.61 (s, 2H), 7.26 (d, J=8.6 Hz, 2H), 8.01 (d, J=8.6 Hz, 2H), 8.32 (s, 4H); .sup.13C NMR (100 MHz, CDCl.sub.3): δ 21.0, 66.7, 122.2, 123.5, 129.3, 131.0, 131.3, 134.6, 150.6, 155.0, 164.0, 168.4, 189.9; FIRMS (ESI): [M+H].sup.+ calcd for C.sub.17H.sub.13NO.sub.7+H: 344.0770. found: 344.0778.

2-(3,4 Dimethoxyphenyl)-2-oxoethyl 4-nitrobenzoate (IIf)

(28) ##STR00014##

(29) Yield: 74%, colorless solid, Mp: 162-163° C.; IR (Nujol, cm.sup.−1): 720, 1021, 1131, 1235, 1376, 1460, 1524, 1684, 1725, 2855, 2925; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 3.95 (s, 3H), 3.98 (s, 311), 5.60 (s, 2H), 6.92 (d, J=8.3 Hz, 1H), 7.51-7.54 (m, 2H), 8.33 (s, 4H); .sup.13C NMR (100 MHz, CDCl.sub.3): δ 55.9, 56.0, 66.6, 110.0, 110.1, 122.1, 123.6, 127.1, 131.0, 134.9, 149.5, 150.8, 154.1, 164.1, 189.5; HRMS (ESI): [M+H].sup.+ calcd for C.sub.17H.sub.15NO.sub.7+H: 346.0922. found: 346.0927.

1-Oxo-2,3-dihydro-1H-inden-2-yl 4-nitrobenzoate (IIg)

(30) ##STR00015##

(31) Yield: 72%, colorless solid, Mp: 199-200° C.; IR (Nujol, cm.sup.−1): 713, 1122, 1273, 1349, 1374, 1522, 1604, 1709, 1722, 2846, 2923; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 3.23 (dd, J=17.0, 4.9 Hz, 1H), 3.82 (dd, J=17.0, 8.1 Hz, 1H), 5.70 (dd, J=8.1, 4.9 Hz, 1H), 7.44-7.53 (m, 2H), 7.68 (d, J 7.7 Hz, 1H), 7.86 (d, J 7.7 Hz, 1H), 8.30 (s, 4H); .sup.13C NMR (125 MHz, CDCl.sub.3): δ 33.4, 75.0, 123.6, 124.7, 126.7, 128.4, 131.1, 134.5, 134.7, 136.1, 150.1, 150.9, 164.1, 199.3; HRMS (ESI): [M+H].sup.+ calcd for: C.sub.16H.sub.12NO.sub.5+H: 298.0715. found: 298.0720.

2-Oxo-1,2-diphenylethyl 4-nitrobenzoate (IIh)

(32) ##STR00016##

(33) Yield: 81%, colorless solid, Mp: 114-115° C.; IR (Nujol, cm.sup.−1): 762, 1097, 1288, 1341, 1374, 1462, 1522, 1692, 1720, 2851, 2923; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 7.13 (s, 111), 7.41-7.58 (m, 8H), 7.99 (d, J=7.2 Hz, 2H), 8.28 (s, 4H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 78.7, 123.5, 128.7, 128.8, 129.3, 129.7, 131.1, 133.2, 133.6, 134.4, 134.8, 150.7, 164.0, 192.6: HRMS (ESI): [M+Na].sup.+ calcd for: C.sub.21H.sub.15NO.sub.5+Na: 384.0848. found: 384.0853.

1-Oxo-1-phenylpropan-2-yl 4-nitrobenzoate (IIi)

(34) ##STR00017##

(35) Yield: 81%, colorless solid, Mp: 119-120° C.; IR (Nujol, cm.sup.−1): 721, 965, 1122, 1270, 1374, 1462, 1522, 1599, 1692, 1725, 2851, 2923; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 1.72 (d, J=6.9 Hz, 3H), 6.23 (q, 0.1=6.9 Hz, 1H), 7.52-7.63 (m, 3H), 7.97-8.01 (m, 211), 8.29-8.30 (m, 4H); .sup.13C NMR (100 MHz, CDCl.sub.3); δ 17.2, 72.6, 123.4, 128.4, 128.8, 130.9, 133.7, 134.8, 150.6, 163.9, 195.5; HRMS (ESI): [M+H].sup.+ calcd for: C.sub.16H.sub.13NO.sub.5+H: 300.0872. found: 300.0877.

3-((Tert-butyldimethylsilyl)oxy)-1-oxo-1-phenylpropan-2-yl 4-nitro benzoate (IIj)

(36) ##STR00018##

(37) Yield: 92%, colorless solid, Mp: 77-78° C.; IR (Nujol, cm.sup.−1): 718, 839, 1270, 1371, 1459, 1530, 1695, 1733, 2851, 2917; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 0.00 (s, 3H), 0.02 (s, 3H), 0.82 (s, 9H), 4.18 (d, J=5.1 Hz, 2H), 6.25 (t, J=5.1 Hz, 111), 7.47-7.62 (m, 3H), 8.00-8.04 (m, 2H), 8.29-8.30 (m, 4H); .sup.13C NMR (100 MHz, CDCl.sub.3): δ −5.4, 18.1, 25.6, 29.7, 62.9, 77.3, 123.5, 128.5, 128.7, 131.0, 133.7, 134.8, 135.2, 150.7, 163.9, 194.4; HRMS (ESI): [M+H].sup.+ calcd for: C.sub.22H.sub.27NO.sub.6Si+H: 430.1686. found: 430.1689.

3-(Benzyloxy)-2-oxopropyl 4-nitrobenzoate (IIk)

(38) ##STR00019##

(39) Yield: 79%, colorless solid, Mp: 83-84° C.; IR (Nujol, cm.sup.−1): 718, 1083, 1283, 1374, 1459, 1517, 1722, 1739, 2851, 2823; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 4.21 (s, 2H), 4.64 (s, 2H), 5.23 (s, 2H), 7.37 (s, 5H), 8.28 (d, J=4.3 Hz, 4H); .sup.13C NMR (125 MHz, CDCl.sub.3): δ 67.8, 73.8, 73.9, 123.5, 127.9, 128.3, 128.6, 130.9, 134.6, 136.5, 150.7, 163.8, 200.8; HRMS (ESI): [M+Na].sup.+ calcd for C.sub.17H.sub.15NO.sub.6+Na: 352.0796. found: 352.0801.

2-Oxooctyl 4-nitrobenzoate (IIl)

(40) ##STR00020##

(41) Yield: 71%, colorless solid, Mp: 75-76° C.: IR (Nujol, cm.sup.−1): 717, 1121, 1272, 1352, 1377, 1463, 1536, 1543, 1722, 1733, 2854, 2923; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 0.87-0.93 (m, 3H), 1.26-1.31 (br. s, 6H), 1.67-1.70 (m, 2H), 2.49 (t, J=7.3 Hz, 2H), 4.94 (s, 2H), 8.24-8.35 (m, 4H); .sup.13C NMR (125 MHz, CDCl.sub.3): δ 13.9, 22.4, 23.2, 28.7, 31.5, 38.7, 68.7, 123.5, 130.9, 134.6, 150.7, 163.8, 202.4: HRMS (ESI): [M+H].sup.+ calcd for C.sub.15H.sub.19NO.sub.5+H: 294.1341. found: 294.1347.

2-Oxodecyl 4-nitrobenzoate (IIm)

(42) ##STR00021##

(43) Yield: 76%, colorless solid, Mp: 76-77° C.; IR (Nujol, cm.sup.−1): 713, 1119, 1270, 1374, 1459, 1541, 1610, 1717, 1736, 2857, 2928; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 0.85-0.92 (m, 3H), 1.29 (br. s., 10H), 1.66 (t, J=7.2 Hz, 2H), 2.49 (t, J=7.2 Hz, 2H), 4.94 (s, 2H), 8.24-8.35 (m, 4H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 14.0, 22.5, 23.2, 29.0, 29.0, 29.2, 31.7, 38.6, 68.6, 123.4, 130.8, 134.6, 150.6, 163.7, 202.2; HRMS (ESI): [M+H].sup.+ calcd for C.sub.17H.sub.23NO.sub.5+H: 322.1654. found: 322.1656.

2-Oxo-4-phenylbutyl 4-nitrobenzoate (IIn)

(44) ##STR00022##

(45) Yield: 74%, colorless solid, Mp: 112-113° C.; IR (Nujol, cm.sup.−1): 724, 1089, 1131, 1273, 1347, 1377, 1462, 1523, 1600, 1718, 1732, 2855, 2926; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 2.79-2.87 (m, 211), 2.95-3.03 (m, 211), 4.91 (s, 2H), 7.21-7.31 (m, 511), 8.27-8.34 (m, 4H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 29.2, 40.4, 68.8, 123.6, 126.4, 128.2, 128.6, 131.0, 138.0, 140.2, 150.8, 163.9, 201.7; HRMS [M+Na].sup.+ calcd for: C.sub.17H.sub.15NO.sub.5+Na: 336.0848. found: 336.0856.

2-Ethoxy-2-oxoethyl 4-nitrobenzoate (IIo)

(46) ##STR00023##

(47) Yield: 78%, yellow liquid; IR (neat, cm.sup.−1): 2926, 2983, 1759, 1738, 1732, 1608, 1531, 1349, 1285, 1213, 1121, 1018, 857, 718; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 1.33 (t, J=7.1 Hz, 3H), 4.28 (q, J=7.1 Hz, 2H), 4.89 (s, 2H), 8.25-8.36 (m, 4H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 14.1, 61.5, 123.5, 131.0, 134.5, 150.8, 163.9, 166.9; HRMS (ESI): [M+Na].sup.+ calcd for C.sub.11H.sub.11NO.sub.6+Na: 276.0484. found: 276.0446.

2-Oxotetrahydro-2H-pyran-3-yl 4-nitrobenzoate (IIp)

(48) ##STR00024##

(49) Yield: 69%, colorless solid, Mp: 136-137° C.; IR (Nujol, cm.sup.−1): 718, 1124, 1273, 1377, 1456, 1511, 1602, 1725, 1753, 2857, 2912; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 2.14-2.20 (m, 3H),

(50) 2.51-2.76 (m, 1H), 4.43-4.49 (m, 2H), 5.61-5.67 (m, 1H), 8.25-8.35 (m, 4H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 21.3, 24.8, 68.2, 68.2, 123.5, 131.0, 134.5, 150.7, 163.4, 168.1; HRMS (ESI): [M+H].sup.+ calcd for C.sub.12H.sub.11NO.sub.6+H: 266.0664. found: 266.0663.

2-(Methoxy)-2-oxo-1-phenylethyl 4-nitrobenzoate (IIq)

(51) ##STR00025##

(52) Yield: 72%, yellow liquid; IR (CHCl.sub.3, cm.sup.−1): 718, 1101, 1167, 1269, 1346, 1368, 1508, 1527, 1606, 1731, 1760; .sup.1H NMR (500 MHz, CDCl.sub.3): δ 3.80 (s, 3H), 6.20 (s, 1H), 7.47-7.48 (m, 3H), 7.59-7.60 (m, 2H), 8.32 (s, 4H); .sup.13C NMR (125 MHz, CDCl.sub.3): δ 52.6, 75.4, 123.5, 127.7, 128.9, 129.5, 131.0, 133.3, 134.5, 150.8, 163.7, 168.5; HRMS (ESI): [M+Na].sup.+ calcd for C.sub.16H.sub.13NO.sub.6+Na: 338.0641. found: 338.0649.

2-Oxo-2-phenylethyl benzoate (IIr)

(53) ##STR00026##

(54) Yield: 68%, colorless solid, Mp: 119-120° C.; IR (Nujol, cm.sup.−1): 705, 1015, 1374, 1459, 1596, 1714, 1750, 2851, 2923; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 5.58 (s, 211), 7.48-7.61 (m, 6H), 7.97-8.00 (m, 2H), 8.13-8.17 (m, 2H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 66.2, 127.6, 128.2, 128.73, 129.8, 130.1, 133.1, 133.6, 134.1, 165.7, 191.6; HRMS (ESI): [M+Na].sup.+ calcd for C.sub.15H.sub.12O.sub.3+Na: 263.0683. found: 263.0692.

2-Oxo-2-phenylethyl 3-methylbenzoate (IIs)

(55) ##STR00027##

(56) Yield: 81%, colorless solid, Mp: 94-95° C.; IR (Nujol, cm): 743, 814, 957, 1083, 1198, 1369, 1451, 1585, 1684, 1714, 2857, 2917; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 2.38 (s, 3H), 5.52 (s, 2H), 7.31-7.48 (m, 5H), 7.90-7.95 (m, 4H); .sup.13C NMR (100 MHz, CDCl.sub.3): δ 21.1, 66.2, 127.0,

(57) 127.6, 128.2 128.7, 129.2, 130.3, 133.6, 133.9, 134.1, 137.9, 165.8, 191.7; HRMS (ESI): [M+Na].sup.+ calcd for C.sub.16H.sub.14O.sub.3+Na: 277.0840. found: 277.0848.

2-Oxo-2-phenylethyl 4-bromobenzoate (IIt)

(58) ##STR00028##

(59) Yield: 78%, colorless solid, Mp: 84-85° C.; IR (Nujol, cm.sup.−1): 766, 1012, 1126, 1327, 1588, 1643, 1711, 1732, 2923, 295′6; .sup.1H NMR (200 MHz, CDCl.sub.3): δ 5.57 (s, 211), 7.44-7.64 (m, 5H), 7.94-8.03 (m, 4H); .sup.13C NMR (50 MHz, CDCl.sub.3): δ 66.4, 127.7, 128.3, 128.4, 128.8, 131.4, 131.7, 133.8, 134.1, 165.0, 191.4: HRMS (ESI): [M+Na].sup.+ calcd for C.sub.15H.sub.11BrO.sub.3+Na: 340.9789. found: 340.9799.

2-Oxo-2-phenylethyl 4-chlorobenzoate (IIu)

(60) ##STR00029##

(61) Yield: 75%, colorless solid, Mp: 127-128° C.; IR (Nujol, cm.sup.−1): 753, 1091, 1226, 1273, 1376, 1456, 1595, 1697, 1726, 2724, 2857, 2926; .sup.1H NMR (500 MHz, CDCl.sub.3): δ 5.58 (s, 2H) 7.44-7.56 (m, 5H), 7.97 (d, J=7.3 Hz, 2H) 8.07 8.11 (d, J=7.3 Hz, 2H); .sup.13C NMR (125 MHz, CDCl.sub.3): δ 66.5, 77.0, 127.8, 128.6, 128.8, 128.9, 131.3, 133.9, 134.2, 139.8, 165.0, 191.6; HRMS (ESI): [M+Na].sup.+ calcd for C.sub.15H.sub.11ClO.sub.3+Na: 297.0294. found: 297.0294.

2-Oxo-2-phenylethyl nicotinate (IIv)

(62) ##STR00030##

(63) Yield: 73%, colorless solid, Mp: 64-65° C.: IR (CHCl.sub.3, cm.sup.−1): 753, 1076, 1342, 1463, 1591, 1650, 1695, 1726, 2854, 2870, 2923; .sup.1H NMR (400 MHz, CDCl.sub.3); δ 5.61 (s, 214), 7.44 (dd, J=7.6, 4.9 Hz, 1H) 7.50-7.54 (m, 2H), 7.62-7.64 (m, 1H), 7.97 (d, J=7.5 Hz, 2H), 8.40 (d, J=7.7 Hz, 1H), 8.82 (br. s, 1H), 9.33 (br. s, 1H); .sup.13C NMR (100 MHz, CDCl.sub.3) δ 66.6,

(64) 123.3, 125.6, 127.8, 128.9, 134.0, 134.1, 137.4, 151.2, 153.7, 164.6, 191.1; HRMS (ESI): [M+Na].sup.+ calcd for C.sub.14H.sub.11NO.sub.3+Na: 264.0637. found: 264.0648.

Advantages of the Invention

(65) A new catalytic regio selective method for the preparation of acyloxy carbonyl products in preparative yield from a variety of olefins including aromatic, aliphatic and electron rich at ambient conditions is disclosed. This method is simple, milder and the reagents used are cheap and easy to handle. The process avoids metal catalysts.