Ruthenium(II) complexes containing 2-diphenylphosphinobenzaldehyde: synthesis and catalytic activity in transfer hydrogenation §

Abstract

The reaction of dimers [Ru(η 6-arene)(μ-Cl)Cl] 2 (arene=C 6H 6 ( 2a); 1- iPr-4-C 6H 4Me ( 2b); 1,2,4,5-C 6H 2Me 4 ( 2c); C 6Me 6 ( 2d)) with 2-diphenylphosphinobenzaldehyde ( 1) yields the neutral complexes [Ru(η 6-arene)Cl 2(κ 1- P-2-Ph 2PC 6H 4CHO)] ( 3a– d). Treatment of compounds 3a– d with one equivalent of AgSbF 6 leads to the formation of the monocationic derivatives [Ru(η 6-arene)Cl(κ 2- P, O-2-Ph 2PC 6H 4CHO)][SbF 6] ( 4a– d). When 3a– d are treated with two equivalents of AgSbF 6 in presence of acetone, the dicationic complexes [Ru(η 6-arene)(κ 1- O-Me 2CO)(κ 2- P, O-2-Ph 2PC 6H 4CHO)][SbF 6] 2 (arene=C 6H 6 ( 5a); 1- iPr-4-C 6H 4Me ( 5b); 1,2,4,5-C 6H 2Me 4 ( 5c); C 6Me 6 ( 5d)) are obtained. Complexes 3– 5a– d have proven to be active catalysts in transfer hydrogenation of acetophenone by propan-2-ol.