method for the highlydiastereoselective preparation of anti tertiary homoallylic alcohols has been developed. The reaction of allyltitanocenes, generated by the reductive titanation of various allylic substrates with a titanocene(II) species, with a variety of ketones produced the anti tertiary homoallylic alcohols in good diastereoselectivity, even when using sterically less congested ketones (see scheme;
Generation of Allylic Indium by Hydroindation of 1,3-Dienes and One-Pot Reaction with Carbonyl Compounds
作者:Naoki Hayashi、Hiroyuki Honda、Makoto Yasuda、Ikuya Shibata、Akio Baba
DOI:10.1021/ol061797n
日期:2006.9.1
A hydroindation of 1,3-dienes by dichloroindium hydride (HInCl2) generates allylic indiums that react with carbonyl or imine moieties in a one-pot treatment. The former reaction proceeds in a radical manner, and the latter is ionic allylation. Moreover, both reactions require no additives such as radical initiators, Lewis acids, or transition metal catalysts.