New optically active organoantimony (BINASb) and bismuth (BINABi) compounds comprising a 1,1′-binaphthyl core: synthesis and their use in transition metal-catalyzed asymmetric hydrosilylation of ketones

✍ Scribed by Shuji Yasuike; Satoru Okajima; Kentaro Yamaguchi; Hiroko Seki; Jyoji Kurita

• Book ID: 104205410
• Publisher: Elsevier Science
• Year: 2003
• Tongue: French
• Weight: 245 KB
• Volume: 59
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(03)00740-3

✦ Synopsis

Racemic 2,2 0 -bis[diarylstibano]-1,1 0 -binaphthyls [(^)-BINASbs] and 2,2 0 -bis[di(p-tolyl)bismuthano]-1,1 0 -binaphthyl [(^)-BINABi], which are the antimony and bismuth congeners of BINAP, have been prepared from 2,2 0 -dibromo-1,1 0 -binaphthyl (DBBN) via 2,2 0 -dilithio-1,1 0 -binaphthyl intermediate by treatment with the appropriate metal halides [(p-Tol) 2 SbBr, Ph 2 SbBr and (p-Tol) 2 BiCl]. The optical resolution of the (^)-BINASbs could be achieved via the separation of a mixture of the diastereomeric Pd-complexes derived from the reaction of (^)-BINASbs with di-m-chlorobis{(S)-2-[1-(dimethylamino)-ethyl]phenyl-C 1 ,N}dipalladium(II). Optically active (R)-BINASb and (R)-BINABi could be also obtained from optically active (R)-DBBN by the same procedure. The enantiopure BINASbs have been shown to be effective chiral ligands for the rhodium-catalyzed asymmetric hydrosilylation of ketones.