Organocatalytic enantioselective and (Z)-selective allylation of 3-indolylmethanol via hydrogen-bond activation†
Abstract
An organocatalytic asymmetric allylation of 3-indolylmethanol has been established via hydrogen-bond activating mode, which directly assembles isatin-derived 3-indolylmethanols and o-hydroxystyrenes into chiral allyl-substituted oxindoles with one all-carbon quaternary stereogenic center and one newly formed CC bond in excellent enantioselectivity and (Z)-selectivity (up to 97% ee, >20ā:ā1 Z/E ratio). This transformation provides an efficient strategy for asymmetric C3-functionalization of indoles and allylation of 3-indolylmethanols with precise control of the stereoselectivity in the formation of CāC and CC bonds.