Diastereoselective Nickel-Catalyzed Reductive Aldol Cyclizations Using Diethylzinc as the Stoichiometric Reductant: Scope and Mechanistic Insight
作者:Pekka M. Joensuu、Gordon J. Murray、Euan. A. F. Fordyce、Thomas Luebbers、Hon Wai Lam
DOI:10.1021/ja0775624
日期:2008.6.1
In the presence of diethylzinc as a stoichiometric reductant, Ni(acac) 2 functions as an efficient precatalyst for the reductive aldol cyclization of alpha,beta-unsaturated carbonyl compounds tethered to a ketone electrophile through an amide or an ester linkage. The reactions are tolerant of a wide range of substitution at both alpha,beta-unsaturated carbonyl and ketone components and proceed smoothly
Diastereoselective Cobalt-Catalyzed Alkylative Aldol Cyclizations Using Trialkylaluminum Reagents
作者:Mairi E. Rudkin、Pekka M. Joensuu、William S. MacLachlan、Hon Wai Lam
DOI:10.1021/ol800883b
日期:2008.7.17
Co(acac)2.2H2O serves as an effective precatalyst for alkylative aldol cyclizations of alpha,beta-unsaturated amides with ketones using trialkylaluminum reagents. These reactions provide beta-hydroxylactams containing three contiguous stereocenters with high levels of diastereoselection.
Diastereoselective Cobalt-Catalyzed Reductive Aldol Cyclizations Using Diethylzinc as the Stoichiometric Reductant
作者:Hon Wai Lam、Pekka M. Joensuu、Gordon J. Murray、Euan A. F. Fordyce、Oscar Prieto、Thomas Luebbers
DOI:10.1021/ol061329d
日期:2006.8.1
text] Cobalt catalysis enables a new method for the generation of zinc enolates using diethylzinc to reduce alpha,beta-unsaturated amides. This method has been applied to a high-yielding diastereoselective reductive aldol cyclization.