The application of Pd-complexes of trans-2,5-dialkylpyrrolidinyl-benzyldiphenylphosphines to enantioselective allylic alkylation

The preparation of cationic palladium (eta(3)-C3H5) complexes 6 and 7, poss essing an enantiopure trans-2,5-dialkylpyrrolidinyl unit, is described. The se complexes were applied to the enantioselective alkylation of the test su bstrate, 1,3-diphenylpropenyl acetate 8, with dimethyl malonate in good to high conversions with enantioselectivities of up to 90% ee for the 2,5-diet hylpyrrolidinyl substituted complex 7. Attempts to optimise reaction condit ions included variation of solvent and temperature and the source of the ma lonate nucleophile. (C) 1998 Elsevier Science Ltd. All rights reserved.