Highly functionalized tertiary-carbinols and carbinamines from the asymmetric γ-alkoxyallylboration of ketones and ketimines with the borabicyclodecanes

Abstract

The first asymmetric γ-alkoxyallylboration of representative ketones provides β-alkoxy tert-homoallylic alcohols 10 whose diastereoselectivities range from 99% syn (acetophenone) to 99% anti (pinacolone) both with high ee (>95%). This distribution is attributable to the c/t isomerization of the BBD reagents and the greater reactivity of 7 vs 1 and of aromatic vs alkyl ketones. A ketone-based direct synthesis of a fostriecin intermediate and the tert-amine 26 are reported, each with high selectivities.