Chiral P,N-ligands based on ketopinic acid in the asymmetric Heck reaction
1Department of Chemistry, Washington University, One Brookings Drive, Campus Box 1134, St. Louis, Missouri 63130, USA. srg@wuchem.wustl.edu
Abstract:
[figure: see text] Novel chiral P,N-ligands were synthesized from (1S)-(+)-ketopinic acid using palladium-catalyzed coupling reaction of a vinyl triflate and either a diarylphosphine or a dialkylphosphine as the key step. Palladium complexes of these ligands are efficient catalysts for asymmetric Heck reaction between aryl or alkenyl triflates and cyclic alkenes. Products were obtained with good to excellent enantioselectivity from arylation and alkenylation of 1,2-dihydrofuran, cyclopentene, and 4,7-dihydro-1,3-dioxepin.
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