B. El Ali et al., Pd(II) - dppb and syngas catalyze regioselective hydroesterification of terminal alkynes under neutral conditions, TETRAHEDR L, 42(12), 2001, pp. 2385-2387
Palladium(II) regioselectively catalyzes the hydroesterification of termina
l alkynes under syngas forming alpha,beta -unsaturated esters 3 and 4 in ex
cellent chemical yields under neutral conditions. The high selectivity for
the linear ester 4 was obtained with a catalytic system that includes Pd(II
), 1,4-bis(diphenylphosphino)butane (dppb) and CO/H-2 in CH2Cl2 as solvent.
The control of the regioselectivity depends strongly upon the type of liga
nd, the solvent and the use of the syngas mixture. (C) 2001 Elsevier Scienc
e Ltd. All rights reserved.