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Chiral Bifunctional Phosphine‐Carboxylate Ligands for Palladium(0)‐Catalyzed Enantioselective C−H Arylation
Author(s) -
Yang Lei,
Neuburger Markus,
Baudoin Olivier
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201712061
Subject(s) - bifunctional , chemistry , enantioselective synthesis , metalation , phosphine , deprotonation , palladium , ligand (biochemistry) , moiety , kinetic resolution , carboxylate , combinatorial chemistry , stereochemistry , catalysis , organic chemistry , ion , biochemistry , receptor
Abstract Previous enantioselective Pd 0 ‐catalyzed C−H activation reactions proceeding via the concerted metalation‐deprotonation mechanism employed either a chiral ancillary ligand, a chiral base, or a bimolecular mixture thereof. This study describes the development of new chiral bifunctional ligands based on a binaphthyl scaffold which incorporates both a phosphine and a carboxylic acid moiety. The optimal ligand provided high yields and enantioselectivities for a desymmetrizing C(sp 2 )−H arylation leading to 5,6‐dihydrophenanthridines, whereas the corresponding monofunctional ligands showed low enantioselectivities. The bifunctional system proved applicable to a range of substituted dihydrophenanthridines, and allowed the parallel kinetic resolution of racemic substrates.