Alcohol activation by [Ir (COD) (tris (pyrazol-1-yl) methane)]+ and [Ir (COD)(tris(pyrazol-1-yl)ethane]+ cations: formation of alkoxycarbonyl derivatives [(tpzm)IrH(CO2R?)(CO)]+ and [(tpze)IrH(CO2R?)(CO)]+ [R?=Me, Et, i-Pr)

Abstract

The reactions of iridium and rhodium complexes derived from tris(pyrazolyl)methane (tpzm) and tris(pyrazolyl)ethane (tpze) have been examined. One of the most interesting reactions involves the formation of alkoxycarbonyl derivatives of iridium tris(pyrazolyl)alkanes from carbon monoxide and alcohols. In the case of rhodium derivatives, a dimer of formula [(tpzm)iRh2 (CO)3](ClO4h has been obtained. A careful 1H and 13C NMR study has allowed assignment of all the signals of the compound [(tpzm)IrH(CO2Me)(CO)]BF4