Pd-catalyzed asymmetric allylic alkylation using furanoside diphosphinite ligands

We have tested furanoside diphosphinite ligands 7 and 8, derived from inexpensive d-(+)-xylose, in the Pd-catalyzed allylic alkylation of two substrates with different steric properties. Enantiomeric excesses of up to 31% with good activities were obtained in the Pd-catalyzed allylic alkylation of substrate rac-1,3-diphenyl-3-acetoxyprop-1-ene 9 with dimethylmalonate as nucleophile. Our results show that the absolute configuration at carbon C-3 of the carbohydrate backbone controlled the sense of enantioselectivity. Models for asymmetric induction are discussed based on the absolute stereochemistry of the product.

Graphical abstractFuranoside diphosphinite ligands were tested in the Pd-catalyzed allylic alkylation. Enantiomeric excesses of up to 31% with good activities were obtained. Our results show that the absolute configuration at carbon C-3 of the carbohydrate backbone controlled the sense of enantioselectivity. Models for asymmetric induction are discussed based on the absolute stereochemistry of the product.Figure optionsDownload full-size imageDownload as PowerPoint slide