Addition of arylmagnesium bromides to aryl(alkyl)acetylenes proceeded in the presence of an iron catalyst and a N-heterocyclic carbene ligand to give high yields of the corresponding alkenylmagnesium reagents, which were transformed into tetrasubstituted alkenes by subsequent treatment with electrophiles. [reaction: see text]
Versatile Relay and Cooperative Palladium(0)<i>N</i>-Heterocyclic Carbene/Copper(I)<i>N</i>-Heterocyclic Carbene Catalysis for the Synthesis of Tri- and Tetrasubstituted Alkenes
作者:Mathieu Lesieur、Yannick D. Bidal、Faïma Lazreg、Fady Nahra、Catherine S. J. Cazin
DOI:10.1002/cctc.201500268
日期:2015.7.13
Two new and efficient dual catalytic procedures for the synthesis of tri‐ and tetrasubstituted alkenes using aryl bromides and chlorides are reported. The formation of these vinyl arenes occurs independently in a one‐pot relay and a one‐pot cooperative procedure using well‐defined Pd and Cu N‐heterocycliccarbene (NHC) complexes. Mechanistic studies were performed to elucidate the key role of the solvent