Stereoselective alkylation of [2-(diphenylphosphino)ferrocenyl]acetonitrile
作者:Martin Lamač、Petr Štěpnička
DOI:10.1016/j.inoche.2005.12.003
日期:2006.3
Deprotonation of racemic [2-(diphenylphosphino)ferrocenyl]acetonitrile (1) with NaN(SiMe3)(2) in THF followed by reaction with electrophiles MeI and Ph2PCl affords the substituted nitriles, 2-[2-(diphenylphosphino)ferrocenyl]propionitrile (2a) and 2-(diphenylphosphino)-[2-(diphenylphosphino)ferrocenyl]acetonitrile (2b), respectively. Whereas the former reaction yields a 15:1 mixture of isomers differing in configuration at the alkylated alpha-carbon from which the major diastereoisomer can be isolated by simple recrystallization, the latter gives 2b as a single diastereoisomer. The dominating product of the methylation reaction was characterized by X-ray diffraction analysis as (S,R-p/,R,S-p)-2a, which is in accordance with the possible access of the electrophile towards deprotonated 1. (C) 2006 Elsevier B.V. All rights reserved.