Cinnamyl chlorides undergo selective S N 2' allylic substitution by Grignard reagents using catalytic amount (1 mol%) of CuCN and 1-2 mol% trivalent phosphorus ligand, in dichloromethane. With chiral phosphorus ligands derived from TADDOL ee's up to 73% could be obtained.
This mini-review discusses the rapidly growing field of asymmetric copper-catalyzed chemistry. Although the allylic substitution has been less studied than the conjugate addition, recent breakthroughs have made this methodology a very valuable synthetic tool. Thus, a primary allylic halide or phosphate reacts with Grignard or diorganozinc reagents to afford the S N ' product (or γ-product) in high regio-and enantioselectivities. Besides the results of the authors, we present also other, different approaches to this reaction, with emphasis on the organometallic and the type of chiral ligand used.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.