Catalytic Asymmetric Vinylation of Ketone Enolates
作者:André Chieffi、Ken Kamikawa、Jens Åhman、Joseph M. Fox、Stephen L. Buchwald
DOI:10.1021/ol0159470
日期:2001.6.1
[see reaction]. A protocol for the catalytic asymmetric vinylation of ketoneenolates has been developed. Key to the success of this process was the development of new electron-rich chiral monodentate ligands.
Chloroacetylenes as Michael acceptors. II. Direct ethynylation and vinylation of tertiary enolates.
作者:Andrew S. Kende、Pawel Fludzinski
DOI:10.1016/s0040-4039(00)87345-1
日期:1982.1
The reaction of ClCCCl, PhCCCl and PhSCCCl with a variety of tertiaryenolates leads in 43–90% yields to α-chloroethynyl, α-phenylethynyl and α-thiophenylethynyl derivatives. The −CCCl group is smoothly converted to −CCH using copper powder in HOAc/THF, or is directly reduced (H2/Lindlar catalyst) to the −CHCH2 group, thus providing facile access to many α-ethynyl and α-vinyl ketones and esters
The present invention provides transition-metal-catalyst-based methods for the arylation and vinylation of activated methyl, methylene, and methine carbons with aryl halides, vinyl halides, and the like. The methods of the invention provide several improvements over existing methods, including the ability to synthesize efficiently and under mild conditions α-aryl and α-vinyl products from a wide range of starting materials, including ketones, esters, hydrazones, and imines. Furthermore, the methods of the invention may be used in an asymmetric sense, i.e. to produce enantiomerically-enriched chiral α-aryl and α-vinyl products.