A SIMPLE AND CONVENIENT PREPARATION OF [(PH(3)P)(4)RH-2(MU-OH)(2)] AND ITS REACTIONS WITH C-H, O-H, AND M-H ACIDS

A simple and efficient procedure was developed for the preparation of [(Ph(3)P)(4)Rh-2(mu-OH)(2)], 1, from Wilkinson's catalyst and aqueous KOH under biphasic conditions (75-85% yield). Complex 1 reacted with c yclopentadiene, methyl malonate, and benzoic acid to give [CpRh(PPh(3) )(2)], [(Ph(3)P)(2)Rh(CH(COOMe)(2))], and [(Ph(3)P)(2)Rh(mu-PhCOO)], r espectively. Depending on the amount of formic acid, the reaction betw een 1 and HCOOH resulted in either decarboxylation and formation of [( Ph(3)P)(2)Rh(H)(2)(HCOOO)] or dehydration affording trans-[(Ph(3)P)(2) Rh(Co)(HCOO)], 6 both transformations being chemospecific. Treatment o f 1 with [CpM(CO)(3)H] (M = Cr, Mo, W) gave heterobinuclear complexes, [(Ph(3)P)(2)Rh(mu-Co)(2)M(CO)Cp], in excellent yield. The structure o f 6 was confirmed by X-ray analysis.