SYNTHESIS OF 1,3-DIENYL COMPLEXES OF RUTHENIUM(II) BY FACILE HYDRORUTHENATION DEHYDRATION OF PROPARGYLIC ALCOHOLS

Reaction of [RuClH(CO)(PPh3)2(BSD)](BSD = 2,1,3-benzoselenadiazole) with the propargylic alcohols HC=C-CR2OH (CR2 = CMe2 or cyclo-C6H10) leads to the sigma-vinyl derivatives [RuCl(CH=CHCR2OH)(CO)(PPh3)2(BSD)] whereas the same alcohols when treated with [RuClH(CO)(PPh3)3] followed by BSD yield (via [RuCl(CH=CHCR2OH)(CO)(PPh3)2.3]), the dehydrated sigma-dienyl compounds [RuCl{CH=CHC(=CH2)Me}(CO)(PPh3)2(BSD)], and [RuCl{CH=CHC6H9}(CO)(PPh3)2(BSD)]. The last complex is also the product of the reaction of [RuClH(CO)(PPh3)2(BSD)] with 1-ethynyl cyclohexene. Dehydration of the vinylic alcohol complexes is also induced by trifluoroacetic anhydride.