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Inorganic base-mediated double carbonylation of iodobenzene to give phenylglyoxylic acid catalyzed by palladium complexes
Journal of Molecular
41 (1987) 379 - 383
Catalysis,
379
Letter
Inorganic Base-mediated Double Carbonylation of Iodobenzene Phenylglyoxylic Acid Catalyzed by Palladium Complexes TOSHI-AK1 KOBAYASHI, MASATO TANAKA* National
HIROSHI YAMASHITA,
Chemical Laboratory
for Industry,
(Received December 18,1986;
TOSHIYASU SAKAKURA
to give
and
Yatabe, Ibaraki 305 (Japan)
accepted March 17,1987)
Over the past few years, double carbonylation has received great interest. In palladium complex-catalyzed reactions, a-keto amides, imines of a-keto amides, a-keto esters and a-keto acids are obtained depending on the nucleophiles [ 1,2]. The reactions are normally effected in the presence of RX+2CO+HNu
Base, -HX
-
Pd catalyst RCoCoNu
amines to trap hydrogen halide, which is liberated during the process. From a practical viewpoint, it is certainly desirable to substitute cheap inorganic bases for amines. Although several results along this line have been reported, the selectivity for double carbonylation is disappointing. In this communication, we disclose the first successful use of inorganic bases in palladium-catalyzed double carbonylation. A typical procedure was as follows: In a 50 ml stainless steel autoclave, iodobenzene (2.0 mmol), water (0.10 ml, 5.5 mmol), calcium hydroxide (2.5 mmol), dichlorobis(triphenylphosphine)palladium (0.02 mmol), and t-butanol (3 ml) were placed under nitrogen atmosphere. Carbon monoxide was charged up to 150 atm at room temperature, and the autoclave was heated in an oil bath at 100 “C for 12 h. After cooling to room temperature, the gas was discharged and the reaction mixture was acidified with hydrochloric acid, then extracted with ether. Ether was evaporated and the residue was methylated with diazomethane to transform free acids to methyl esters. The yields in methyl esters were determined by gas chromatography. The results are summarized in Table 1. Both rate and selectivity of the double carbonylation were affected by the nature of the inorganic bases. In the series of alkali and alkaline earth metal hydroxides, the selectivity sequence was Li > Na > K > Cs and Ca > Sr > Ba > Mg, respectively. It is interesting to note that these sequences are the same as observed in the cobalt complex-catalyzed double carbonyla*Author to whom correspondence 0304-5102/87/$3.50
should be addressed. 0 Elsevier Sequoia/Pfinted
in The Netherlands
LiOH NaOH KOH CsOH Ca(CH)s Ca(CH)s Ca(OH)2 Ca(CH)s Ca( OH )2 Ca(CH)2 Ca(CH)2 Ca(CH)s Ca(CH)s Ca(CH)z Ca(CH)s Ca(CH)z Ca(CH)s Ca(CH)2 Ca(CH)s Ca(CH)s Ca(CH)z Ca(CH)s Ca(CH)2 Ca(CH)s
t-butanol t-butanol t-butanol PdWW&H,M2 t-butanol Pd’WPtWWd, t-butanol PdWWd%h12 t-butanol PdWW&,)& t-butanol PdWP(‘WsM2 t-butanol Pd’&[P(~&)312 t-butanol PdWWWWdW212 t-butanol PdWP(CHd,GWIz t-butanol PdCMWW31, t-butanol PdC.W’WMd, t-butanol PdWP(C&M, PdClz[P(CH2CH(CH3)2)312t-butanol PdClz[P(cyclo-C6H11)3~ t-butanol PdC12(dppe)e t-butanol PdC12(dppb)f t-butanol t-butanol PdCW&CN)2 Pd/C (5%) t-butanol PdO t-butanol dioxane PdCMWciWd2 benzene PdWP(GW312 tetrahydrofuran PdChFYG-W31, dichloromethane PdWP(WM& HMPAz PdWWWsM2 acetonitrile PdWWcW312 DMIh PdWWX%I, ‘y-butyrolactone PdWW&sM2
PdWW&)312 PdCMP(W%l,
MiWW2 CaW-02 WOW2 BaKW2
Solvent
Catalyst
Base
23.7 99.4 99.2 99.2 97.4 66.2 87.6 97.9 96.8 92.3 80.7 91.3 92.4 95.0 61.4 71.6 86.2 92.3 96.8 91.0 91.7 59.7 99.4 53.4 99.2 95.6 100 34.9
Conversion of C&I (%)
Phenylglyoxylic acid synthesis via double carbonylation of iodobenzenea
TABLE 1
0.5 44.0 23.8 14.3 23.2 10.3 7.8 3.7 67.0 70.7 67.2 77.0 71.5 75.2 26.0 19.8 44.9 54.6 52.8 52.9 56.3 25.9 53.7 20.8 12.2 55.3 24.4 0
C&COCOzH 11.2 46.4 71.8 77.0 67.7 40.0 62.8 79.5 22.2 12.8 7.2 11.4 12.6 13.0 26.9 49.1 31.6 28.8 31.9 30.4 29.9 18.5 36.6 18.4 84.5 33.8 70.6 34.4
W-WO2H
Products and yieldsb (%)
4.3 48.7 24.9 15.7 25.5 20.5d ll.Od 4.4d 75.3 84.7 90.3 87.1 85.0 85.3 49.1 28.7 58.7 65.5 62.3 63.5 65.3 58.3 59.5 53.1 12.6 62.1 25.6 0
Selectivity in C&IsCOC02HC (%)
WOW2
PdCWWM,
PdCW(C6Hs)sJ2
PdWWYW312 I’d W%Hs )314
dimethyl sulfoxide t-butanol t-butanol dioxane
100 83.2 100 98.0
0.5 22.2 60.5 86.4
99.4 46.3 35.0 1.4
0.5 32.4 63.4 92.1
VeH51 2.0 mmol, M(OH)s 2.5 mmol or MOH 5.0 mmol, Hz0 5.5 mmol, catalyst 0.02 mmol, solvent 3 ml, &CO) = 150 atm at room temperature, 100 “C, 12 h. bProducts were determined as methyl esters, and yields are based on &I-I51 charged. clOO x C&15COC02H/(CeH5COC0,H + C&IsC02H). dTraces of benxaldehyde and mandelic acid were also detected. e1,2-Bis(diphenylphosphino)ethane. fl,4-Bis(diphenylphosphino)butane. cHexamethylphosphoric triamide. h1,3-Dimethyl-2-imidazolidinone. ‘p(C0) = 300 atm.
Ca(CH)2 Ca( OH),’ Ca( OH),’
382 tion of benzyl halide [3,4], despite the di~imil~ty of the proposed mechanisms of the double carbonylation reactions catalyzed by paladin [ 51 and cobalt complexes 161. As for the ligand effect, the more basic phosphines exhibited better selectivities for double carbonylation, as verified by the increasing trend, P(C,H,), < P(CH3)(C6H& < P(CH&(C6H5) < P(CH&. In addition, the use of P[CWWCHd213, which is much more basic than P(C6H&, resulted in a much higher selectivity, though these ligands are of similar steric bulkiness (Tolman’s cone angles being 143 and 145”, respectively) [7]. However, ~(~Y~~~-~6~J[, 113, a strongly basic but too bulky phosphine, displayed an inferior performance in terms of both the activity and the selectivity. The performance of bisphosphines (dppe and dppb) was worse than that of P(CH3)(C6H~)2 which is a monophosph~e of similar basicity. The selectivities achieved by the use of catalysts without any ancillary ligands were relatively high. As was observed in the at-keto ester synthesis [2e], the selectivity for double carbonylation decreased when the P(CJi,),/Pd ratio was increased from 2 to 4 (e.g., using Pd[P(C,H,),],). On the other hand, boosting the CO pressure to 300 atm resulted in improvement of the selectivity. The nature of the solvent was another important factor which affected the course of the reaction: dioxane, tetrahydrofuran and acetonitrile were much better solvents than t-butanol, whereas the reactions in y-butyro‘lactone or dimethyl sulfoxide selectively gave benzoic acid. All these observations combined led us to the highest yield of phenylglyoxylic acid, 86.4%, achieved in the reaction effected with the P(CH3)3 complex catalyst and Ca(OH)2 in dioxane solvent under 300 atm of carbon monoxide for 12 h. In summary, this paper offers a new and efficient procedure for the synthesis of cy-keto acids via palladium-catalyzed double carbonylation of organic halides. Extension of the procedure to other halides, as well as to other types of palladium-catalyzed double carbonylation, is in progress. References 1 (a) T. Kobayashi and M. Tanaka, J. Organometali. Chem.. 233 (1982) C64; (b) T. Kobayashi and M. Tanaka, Jpn. Pat. Kokai 83-213724 (1983) to Agency of Industrial Science and Technology, Japan; (c) M. Tanaka, T. Kobayashi, T. Sakakura, H. Itatani, S. Danno and K. Zushi, J. Mol. CataL, 32 (1985) 115; (d) M. Tanaka, T. Kobayashi and T. Sakakura, J. Chem. Sot., Chem. Commun., (1985) 831; (e) H. Yamashita, T. Kobayashi, T. Sakakura and M. Tanaka, Shokubai fCatalyst), 28 (1986) 150. 2 (a) F. Ozawa, H. Soyama, T. Yamamoto and A. Yamamoto, Tetrahedron Lett., 23 (1982) 3383; (b) F. Ozawa, H. Soyama, H. Yanagihara, I. Aoyama, H. Takino, K. Izawa, T. Yamamoto and A. Yamamoto, J. Am. Chem. Sot., 107 (1985) 3235; (c) F. Ozawa, N. Kawasaki, T. Yamamoto and A. Yamamoto, Chem. Lett., (1985) 567; (d) H. Itatani, S. Danno and K. Zushi, Jpn. Pat. Kokai 85-19750 (1985) to Ube Industries; (e) B. Morin, A. Hirschauer, F. Hugues, D. Commereuc and Y. Chauvin, J. Mol. CataL, 34 (1986) 317. 3 J. Gautier-Lafaye, private communication. 4 M. El-Chahawi, Jpn. Pat. Kokai 80-4398 (1980) to Dynamit Nobel A.G.
5 (a) J.-T. Chen and A. Sen, J. Am. Chem. Sot., 106 (1984) 1506; (b) F. Ozawa, T. Sugimoto, Y. Yuasa, M. Santra, T. Yamamoto and A. Yamamoto, Organometallics, 3 (1984) 683; (c) F. Ozawa, T. Sugimoto, T. Yamamoto and A. Yamamoto, Organometallics, 3 (1984) 692. 6 L. Cassar, Ann. N.Y. Acad. Sci., 333 (1980) 208. 7 C. A. Tolman, Chem. Rev., 77 (1977) 313.
41 (1987) 379 - 383
Catalysis,
379
Letter
Inorganic Base-mediated Double Carbonylation of Iodobenzene Phenylglyoxylic Acid Catalyzed by Palladium Complexes TOSHI-AK1 KOBAYASHI, MASATO TANAKA* National
HIROSHI YAMASHITA,
Chemical Laboratory
for Industry,
(Received December 18,1986;
TOSHIYASU SAKAKURA
to give
and
Yatabe, Ibaraki 305 (Japan)
accepted March 17,1987)
Over the past few years, double carbonylation has received great interest. In palladium complex-catalyzed reactions, a-keto amides, imines of a-keto amides, a-keto esters and a-keto acids are obtained depending on the nucleophiles [ 1,2]. The reactions are normally effected in the presence of RX+2CO+HNu
Base, -HX
-
Pd catalyst RCoCoNu
amines to trap hydrogen halide, which is liberated during the process. From a practical viewpoint, it is certainly desirable to substitute cheap inorganic bases for amines. Although several results along this line have been reported, the selectivity for double carbonylation is disappointing. In this communication, we disclose the first successful use of inorganic bases in palladium-catalyzed double carbonylation. A typical procedure was as follows: In a 50 ml stainless steel autoclave, iodobenzene (2.0 mmol), water (0.10 ml, 5.5 mmol), calcium hydroxide (2.5 mmol), dichlorobis(triphenylphosphine)palladium (0.02 mmol), and t-butanol (3 ml) were placed under nitrogen atmosphere. Carbon monoxide was charged up to 150 atm at room temperature, and the autoclave was heated in an oil bath at 100 “C for 12 h. After cooling to room temperature, the gas was discharged and the reaction mixture was acidified with hydrochloric acid, then extracted with ether. Ether was evaporated and the residue was methylated with diazomethane to transform free acids to methyl esters. The yields in methyl esters were determined by gas chromatography. The results are summarized in Table 1. Both rate and selectivity of the double carbonylation were affected by the nature of the inorganic bases. In the series of alkali and alkaline earth metal hydroxides, the selectivity sequence was Li > Na > K > Cs and Ca > Sr > Ba > Mg, respectively. It is interesting to note that these sequences are the same as observed in the cobalt complex-catalyzed double carbonyla*Author to whom correspondence 0304-5102/87/$3.50
should be addressed. 0 Elsevier Sequoia/Pfinted
in The Netherlands
LiOH NaOH KOH CsOH Ca(CH)s Ca(CH)s Ca(OH)2 Ca(CH)s Ca( OH )2 Ca(CH)2 Ca(CH)2 Ca(CH)s Ca(CH)s Ca(CH)z Ca(CH)s Ca(CH)z Ca(CH)s Ca(CH)2 Ca(CH)s Ca(CH)s Ca(CH)z Ca(CH)s Ca(CH)2 Ca(CH)s
t-butanol t-butanol t-butanol PdWW&H,M2 t-butanol Pd’WPtWWd, t-butanol PdWWd%h12 t-butanol PdWW&,)& t-butanol PdWP(‘WsM2 t-butanol Pd’&[P(~&)312 t-butanol PdWWWWdW212 t-butanol PdWP(CHd,GWIz t-butanol PdCMWW31, t-butanol PdC.W’WMd, t-butanol PdWP(C&M, PdClz[P(CH2CH(CH3)2)312t-butanol PdClz[P(cyclo-C6H11)3~ t-butanol PdC12(dppe)e t-butanol PdC12(dppb)f t-butanol t-butanol PdCW&CN)2 Pd/C (5%) t-butanol PdO t-butanol dioxane PdCMWciWd2 benzene PdWP(GW312 tetrahydrofuran PdChFYG-W31, dichloromethane PdWP(WM& HMPAz PdWWWsM2 acetonitrile PdWWcW312 DMIh PdWWX%I, ‘y-butyrolactone PdWW&sM2
PdWW&)312 PdCMP(W%l,
MiWW2 CaW-02 WOW2 BaKW2
Solvent
Catalyst
Base
23.7 99.4 99.2 99.2 97.4 66.2 87.6 97.9 96.8 92.3 80.7 91.3 92.4 95.0 61.4 71.6 86.2 92.3 96.8 91.0 91.7 59.7 99.4 53.4 99.2 95.6 100 34.9
Conversion of C&I (%)
Phenylglyoxylic acid synthesis via double carbonylation of iodobenzenea
TABLE 1
0.5 44.0 23.8 14.3 23.2 10.3 7.8 3.7 67.0 70.7 67.2 77.0 71.5 75.2 26.0 19.8 44.9 54.6 52.8 52.9 56.3 25.9 53.7 20.8 12.2 55.3 24.4 0
C&COCOzH 11.2 46.4 71.8 77.0 67.7 40.0 62.8 79.5 22.2 12.8 7.2 11.4 12.6 13.0 26.9 49.1 31.6 28.8 31.9 30.4 29.9 18.5 36.6 18.4 84.5 33.8 70.6 34.4
W-WO2H
Products and yieldsb (%)
4.3 48.7 24.9 15.7 25.5 20.5d ll.Od 4.4d 75.3 84.7 90.3 87.1 85.0 85.3 49.1 28.7 58.7 65.5 62.3 63.5 65.3 58.3 59.5 53.1 12.6 62.1 25.6 0
Selectivity in C&IsCOC02HC (%)
WOW2
PdCWWM,
PdCW(C6Hs)sJ2
PdWWYW312 I’d W%Hs )314
dimethyl sulfoxide t-butanol t-butanol dioxane
100 83.2 100 98.0
0.5 22.2 60.5 86.4
99.4 46.3 35.0 1.4
0.5 32.4 63.4 92.1
VeH51 2.0 mmol, M(OH)s 2.5 mmol or MOH 5.0 mmol, Hz0 5.5 mmol, catalyst 0.02 mmol, solvent 3 ml, &CO) = 150 atm at room temperature, 100 “C, 12 h. bProducts were determined as methyl esters, and yields are based on &I-I51 charged. clOO x C&15COC02H/(CeH5COC0,H + C&IsC02H). dTraces of benxaldehyde and mandelic acid were also detected. e1,2-Bis(diphenylphosphino)ethane. fl,4-Bis(diphenylphosphino)butane. cHexamethylphosphoric triamide. h1,3-Dimethyl-2-imidazolidinone. ‘p(C0) = 300 atm.
Ca(CH)2 Ca( OH),’ Ca( OH),’
382 tion of benzyl halide [3,4], despite the di~imil~ty of the proposed mechanisms of the double carbonylation reactions catalyzed by paladin [ 51 and cobalt complexes 161. As for the ligand effect, the more basic phosphines exhibited better selectivities for double carbonylation, as verified by the increasing trend, P(C,H,), < P(CH3)(C6H& < P(CH&(C6H5) < P(CH&. In addition, the use of P[CWWCHd213, which is much more basic than P(C6H&, resulted in a much higher selectivity, though these ligands are of similar steric bulkiness (Tolman’s cone angles being 143 and 145”, respectively) [7]. However, ~(~Y~~~-~6~J[, 113, a strongly basic but too bulky phosphine, displayed an inferior performance in terms of both the activity and the selectivity. The performance of bisphosphines (dppe and dppb) was worse than that of P(CH3)(C6H~)2 which is a monophosph~e of similar basicity. The selectivities achieved by the use of catalysts without any ancillary ligands were relatively high. As was observed in the at-keto ester synthesis [2e], the selectivity for double carbonylation decreased when the P(CJi,),/Pd ratio was increased from 2 to 4 (e.g., using Pd[P(C,H,),],). On the other hand, boosting the CO pressure to 300 atm resulted in improvement of the selectivity. The nature of the solvent was another important factor which affected the course of the reaction: dioxane, tetrahydrofuran and acetonitrile were much better solvents than t-butanol, whereas the reactions in y-butyro‘lactone or dimethyl sulfoxide selectively gave benzoic acid. All these observations combined led us to the highest yield of phenylglyoxylic acid, 86.4%, achieved in the reaction effected with the P(CH3)3 complex catalyst and Ca(OH)2 in dioxane solvent under 300 atm of carbon monoxide for 12 h. In summary, this paper offers a new and efficient procedure for the synthesis of cy-keto acids via palladium-catalyzed double carbonylation of organic halides. Extension of the procedure to other halides, as well as to other types of palladium-catalyzed double carbonylation, is in progress. References 1 (a) T. Kobayashi and M. Tanaka, J. Organometali. Chem.. 233 (1982) C64; (b) T. Kobayashi and M. Tanaka, Jpn. Pat. Kokai 83-213724 (1983) to Agency of Industrial Science and Technology, Japan; (c) M. Tanaka, T. Kobayashi, T. Sakakura, H. Itatani, S. Danno and K. Zushi, J. Mol. CataL, 32 (1985) 115; (d) M. Tanaka, T. Kobayashi and T. Sakakura, J. Chem. Sot., Chem. Commun., (1985) 831; (e) H. Yamashita, T. Kobayashi, T. Sakakura and M. Tanaka, Shokubai fCatalyst), 28 (1986) 150. 2 (a) F. Ozawa, H. Soyama, T. Yamamoto and A. Yamamoto, Tetrahedron Lett., 23 (1982) 3383; (b) F. Ozawa, H. Soyama, H. Yanagihara, I. Aoyama, H. Takino, K. Izawa, T. Yamamoto and A. Yamamoto, J. Am. Chem. Sot., 107 (1985) 3235; (c) F. Ozawa, N. Kawasaki, T. Yamamoto and A. Yamamoto, Chem. Lett., (1985) 567; (d) H. Itatani, S. Danno and K. Zushi, Jpn. Pat. Kokai 85-19750 (1985) to Ube Industries; (e) B. Morin, A. Hirschauer, F. Hugues, D. Commereuc and Y. Chauvin, J. Mol. CataL, 34 (1986) 317. 3 J. Gautier-Lafaye, private communication. 4 M. El-Chahawi, Jpn. Pat. Kokai 80-4398 (1980) to Dynamit Nobel A.G.
5 (a) J.-T. Chen and A. Sen, J. Am. Chem. Sot., 106 (1984) 1506; (b) F. Ozawa, T. Sugimoto, Y. Yuasa, M. Santra, T. Yamamoto and A. Yamamoto, Organometallics, 3 (1984) 683; (c) F. Ozawa, T. Sugimoto, T. Yamamoto and A. Yamamoto, Organometallics, 3 (1984) 692. 6 L. Cassar, Ann. N.Y. Acad. Sci., 333 (1980) 208. 7 C. A. Tolman, Chem. Rev., 77 (1977) 313.