Bromoetherification of Alkenyl Alcohols by Aerobic Oxidation of Bromide: Asymmetric Synthesis of 2‐Bromomethyl 5‐Substituted Tetrahydrofurans
作者:Akihiko Tomizuka、Katsuhiko Moriyama
DOI:10.1002/adsc.201801557
日期:2019.3.15
An asymmetricsynthesis of 2‐bromomethyl‐5‐substituted tetrahydrofurans via a chiral‐ruthenium‐catalyzed transfer hydrogenation of 3‐butenyl ketones and bromoetherification of chiral pentenyl alcohols was developed. The inhibition of some side reactions furnished the desired products in high yields with high enantioselectivities. In addition, chiral pentenyl alcohols bearing electron‐donating groups
Copper(I)-catalyzed diastereoselective borylative exo-cyclization of alkenyl ketones with bis(pinacolato)diboron is reported. The reaction of alkenyl aryl ketones under a CuCl/Xantphos catalyst system provides four- or five-membered-ring syn-2-(borylmethyl)cycloalkanol derivatives in good yields with high syn selectivities. The utility of this method is demonstrated by further transformations of the cyclic products.