Asymmetric hydroformylation of conjugated dienes catalyzed by chiral phosphine-phosphite-Rh(I) complex

✍ Scribed by Toshihide Horiuchi; Tetsuo Ohta; Eiji Shirakawa; Kyoko Nozaki; Hidemasa Takaya

• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 503 KB
• Volume: 53
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(97)00471-7

✦ Synopsis

Asymmetric hydroformylation of conjugated dienes has been investigated using (R,S)-BINAPHOS-Rh(I) complex as a catalyst [(R,S)-BINAPHOS = (R)-2-(diphenylphosphino)-l,l'binaphthalen-2'-yl (S)-I,1 '-binaphthalene-2,2'-diyl phosphite]. Optically active 13,~,-unsaturated aldehydes were obtained in high regio-(78-94%) and enantioselectivities (80-97% ee) from l-vinylcyclohexene, 4methyl-l,3-pentadiene, and (E)-l-phenyl-l,3-butadiene. On the other hand, hydroformylation of 1,3butadiene gave achiral product, (E)-and (Z)-3-pentenal, in up to 95% selectivity. (R)-(E)-2-Methyl-3pentenal was formed as the major product from both (E)-and (Z)-l,3-pentadiene, but enantioselectivity of the reaction was low. Mechanistic aspects are also discussed.