P. Hong, T. Mise, H. Yamazaki
Nov 1, 1987
Citations
0
Influential Citations
16
Citations
Journal
Journal of Organometallic Chemistry
Abstract
Abstract Rhodium carbonyl-catalyzed cross-hydrocarbonylation of acetylenes and ethylene with carbon monoxide and hydrogen gives α,β-unsaturated ethyl ketones. Under CO (10 kg cm −2 ) and H 2 (50 kg cm −2 ) at 90°C the reaction of diphenylacetylene with ethylene in the presence of Rh 4 (CO) 12 catalyst gave ( E )-1,2-diphenyl-1-penten-3-one ( 3a ) in 91% yield. Under similar conditions phenylacetylene ( 1d ), 1-hexyne ( 1e ), 3,3-dimethyl-1-butyne ( 1f ), and trimethylsilylacetylene ( 1g ) gave ( E )-1-phenyl-1-penten-3-one ( 3d ), ( E )-4-nonen-3-one ( 3e ), ( E )-6,6-dimethyl-4-hepten-3-one ( 3f ), and ( E )-1-trimethylsilyl-1-pentene-3-one ( 3g ) in 76, 68, 93, and 62% yields, respectively. Thus, the reaction of terminal acetylenes proceeds with high stereo- and regioselectivity: the propionyl group is introduced to the less-sterically hindered acetylenic carbon atom. By comparison of the regioselectivity with that in the formation of 5-ethyl-2(5 H )-furanone ( 2 ), which is obtained in the presence of a hydrogen donor such as alcohol, these reactions are assumed to include a β-acylvinylrhodium complex as the common key intermediate.