Morisaki Y, Imoto H, Hirano K, Hayashi T, Chujo Y. Synthesis of enantiomerically pure P-stereogenic diphosphacrowns and their palladium complexes.
J Org Chem 2011;
76:1795-803. [PMID:
21291270 DOI:
10.1021/jo1024442]
[Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A practical synthetic route for enantiomerically pure P-stereogenic diphosphacrowns was developed by using a P-stereogenic bisphosphine as a chiral building block. Their molecular structures were confirmed by NMR spectroscopy and X-ray crystallography. Complexation of the diphosphacrowns with palladium was carried out, and the corresponding palladium complexes were obtained. The P-stereogenic diphosphacrowns were applicable to the chiral ligand for the asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated ketone catalyzed by palladium. This reaction proceeded smoothly to afford the corresponding 1,4-addition products in high yield with good enantioselectivities.
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