Carbohydrate-Based Pyridine-2-carboxamides for Mo-Catalyzed Asymmetric Allylic Alkylations

Bis(pyridine-2-carboxamides) were prepared from 1,2-diamines obtained from alpha-D-ghlcose and alpha-D-mannose. The ligands were assessed in molybdenum-catalyzed asymmetric allylic alkylations (AAA) by using both methyl (E)-3-phenyl-2-propenyl and methyl rac-1-phenyl-2-propenyl carbonates and dimethyl malonate as nucleophile under microwave irradiation. High enantioselectivity (99 % ee) and high regioselectivity (49:1 in favour of the branched isomer) were observed in reactions of the linear achiral substrate in the presence of 10 mol-% of a catalyst prepared from a ligand derived from glucose. Somewhat lower enantioselectivity (up to 96 % ee) was observed in reactions with the branched racemic carbonate by using the same ligand. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
QC 20100525