Unexpected formation of the isopropylamine complex [2,3,4,5-Ph-4(eta(4)-C4CO)](CO)(2)Ru(H2NCHMe2) in the attempted synthesis of an isopropyl alcohol complex

Abstract

The reaction of [2,3,4,5-Ph-4(eta(4)-C4CO)]Ru(CO)(3) (5a) with Na2CO3 in aqueous acetone followed by low-temperature treatment with NH4Cl was reported to give the material A, which was formulated as the isopropyl alcohol complex [2,3,4,5-Ph-4(eta(4)-C4CO)](CO)(2)Ru(HOCHMe2) (3a). Reinvestigation of this reaction indicates that A is instead the isopropylamine complex [2,3,4,5-Ph-4(eta(4)-C4CO)](CO)(2)Ru(H2NCHMe2) (4a). The formation of 4a is proposed to occur by formation of the imine of acetone followed by reduction of the imine by the (hydroxycyclopentadienyl)ruthenium hydride [2,3,4,5-Ph-4(eta(5)-C4COH)]Ru(CO)(2)H (2a) formed in the reaction of 5a with Na2CO3 in aqueous acetone and subsequent acidification with aqueous NH4Cl.