Nickel(0)-Catalyzed Heck Cross-Coupling via Activation of Aryl C–OPiv Bonds
作者:Andrew R. Ehle、Qi Zhou、Mary P. Watson
DOI:10.1021/ol203322v
日期:2012.3.2
Using a Ni(dppf) catalyst generated in situ, Heck cross-coupling of aryl pivalates with a variety of olefin partners has been accomplished. This method represents one of the first examples of a C C cross-coupling via activation of a strong C-O bond with a nonorganometallic coupling partner. It enables the transformation of phenol-based substrates into styrenyl products without generation of a halogenated byproduct or the use of expensive triflate groups.
An operationally simple approach to (E)-α-halo vinyl sulfides and their applications for accessing stereodefined trisubstituted alkenes
protocol for the synthesis of (E)-α-halo vinyl sulfides has been achieved via a highly regio- and stereoselective hydrohalogenation of alkynyl thioethers using lithium halides in HOAc or propionic acid at room temperature. It permits the formation of (E)-α-chloro and (E)-α-bromo vinyl sulfides in satisfactory yields with good to excellent stereoselectivities. Moreover, this work results in a new method for