Dimerization of 1-alkynes catalyzed by RhCl(PMe3)3. Isolation of the intermediate (alkynyl)(vinyl)rhodium(III) complexes

Article abstract of DOI:10.1016/0022-328X(90)80262-X

The dimerization of 1-alkynes catalyzed by RhCl(PMe3)3 yields conjugated enynes I and II (I/II = 1.4 - 2.4), with a selectivity of 95 - 98 percent.The data indicate that the reaction proceeds by alkyne insertion into the metal-hydride bond of the intermediate (alkynyl)(hydride)Rh^III complexes VII, VIII to give the (alkynyl)(vinyl)Rh^III species cis- (IX) and cis- (X) which were isolated.The thermal decomposition of IX and X in solution gives the enynes I and II correspondingly.