Asymmetric carbonyl addition reactions to benzyloxyaldehydes by binaphthol-titanium catalyst: Anti- vs. Syn-diastereofacial preference in anomalous nonchelation complexation
作者:Koichi Mikami、Satoru Matsukawa、Eiji Sawa、Akinori Harada、Nobuaki Koga
DOI:10.1016/s0040-4039(97)00231-1
日期:1997.3
An anomalous nonchelation diastereofacial selectivity is observed in the titanium-catalyzed carbonyl addition reaction to benzyl-protected alkoxyaldehydes. There is a dichotomy in the sense of syn- vs. anti-diastereofacial preference, dictated by the bulkiness of the migratory group: The sterically demanding silyl group gives syn-diastereofacial preference and the less sterically demanding proton lends to anti-diastereofacial preference. (C) 1997 Elsevier Science Ltd.