Reactions of [RuClH(CO)(PPh3)3] with 2-methyl-2-propen-1-ol. Reversible insertion/β-elimination, and reductive elimination on a 3-hydroxy-2-methylpropyl-C1,O-ruthenium(II) complex

Abstract A hydridoruthenium complex [RuClH(CO)(PPh 3 ) 3 ] ( 1 ) reacts with 2-methyl-2-propen-1-ol at room temperature to give an insertion product, [Ru{CH 2 CH(CH 3 )CH 2 OH}Cl(CO)(PPh 3 ) 2 ] ( 2 ), which undergoes β -elimination of 2-methyl-2-propen-1-ol reversibly in solution. The complex 1 reacts with 2-methyl-2-propen-1-ol under benzene refluxing conditions to produce 2-methylpropan-1-ol, 2-methylpropanal and 2-methyl-2-propenal catalytically in the presence of water. The production of 2-methylpropanal results in formation of two isomers of 2-methylpropanoato complex [RuCl{ η 2 -(CH 3 ) 2 CHCO 2 }(CO)(PPh 3 ) 2 ] ( 3 ). Heating 1 at 80°C in neat 2-methyl-2-propen-1-ol affords a novel ruthenium( O ) complex [Ru{ η 4 -CH 2 C(CH 3 )CHO}-(CO)(PPh 3 ) 2 ] ( 7 ) and a quaternary phosphonium salt [Ph 3 PCH 2 CH(CH 3 )CH 2 OH]Cl ( 8 ) via reductive elimination of 3-chloro-2methylpropan-1-ol from 2 . The molecular structures of 7 and 8 are determined by X-ray crystallography.