Asymmetric Synthesis of P-Stereogenic Homo- and Heterobimetallic Complexes via Selective Monoinsertion of Dialkynylphosphine into the Pd−C Bond of a Palladacycle

Subsequent to their coordination onto chiral cyclopalladated/platinated [1-(dimethylamino)ethyl]naphthalene templates, a series of asymmetric monoinsertions of the carbon−carbon triple bond of dialkynylphosphines into the Pd−C bond of chiral α-methyl N,N-dimethyl benzylamine palladacycles have been demonstrated. These insertion reactions exhibited high regioselectivity and moderate stereoselectivity under mild conditions, and a variety of chiral homo- or heterobimetallic complexes incorporating a newly generated P-stereogenic center were formed. In some instances, the monoinsertion product would subsequently undergo a series of transformations during their purification via column chromatography or upon stirring them with H2O to generate a zwitterionic complex incorporating an additional four-membered ring system with a newly generated C-stereogenic center. The coordination chemistry and the absolute stereochemistry of the monoinsertion products and the transformation products were determined by single-crystal X-ray crystallographic analysis.