Direct Asymmetric α-Allylation of Aldehydes with Simple Allylic Alcohols Enabled by the Concerted Action of Three Different Catalysts
作者:Gaoxi Jiang、Benjamin List
DOI:10.1002/anie.201103263
日期:2011.9.26
catalysis: The title reaction between α‐branched aldehydes and allylic alcohols, which generates all‐carbon quaternary stereogenic centers, constitutes the first asymmetric Tsuji–Trost‐type α‐allylation of carbonyl compounds with allylic alcohol (see scheme). This reaction is catalyzed by three different species, [Pd(PPh3)4], the chiralBrønstedacid TRIP, and benzhydryl amine.
Enantioselective Construction of Quaternary Stereogenic Centers from Tertiary Boronic Esters: Methodology and Applications
作者:Ravindra P. Sonawane、Vishal Jheengut、Constantinos Rabalakos、Robin Larouche-Gauthier、Helen K. Scott、Varinder K. Aggarwal
DOI:10.1002/anie.201008067
日期:2011.4.11
that bear versatile functional groups with quaternary stereogenic centers have been prepared with very high enantioselectivity from tertiaryboronicesters (see scheme; Cb=N,N‐diisopropylcarbamoyl, pin=pinacolato). The preparation of allylboronic esters bearing contiguous quaternary and tertiary stereogenic centers, and applications to natural product synthesis are also reported.