PHOSPHINE BORANES IN COORDINATION CHEMISTRY - AN EFFICIENT METHOD FORTHE SYNTHESIS OF CHIRAL AND ACHIRAL ORGANOPHOSPHORUS PENTACARBONYLTUNGSTEN COMPLEXES

Organophosphorus boranes 1-6 and amine pentacarbonyltungsten complexes 14-20 react under mild conditions, to afford by Ligand exchange the c orresponding W(CO)(5)(PR3) 21-26 derivatives in 63-92% yields. The use of piperazine 13 as a diamine tungsten substituent permits a tandem r eaction which removes the borane group and leads to the formation of t he corresponding organophosphorus tungsten complex. The stereochemistr y of the formation of pentacarbonyltungsten complexes from tertiary ch iral organophosphorus borane compounds proceeds with a high stereosele ctivity and retention of configuration at the chiral P center.