Abstract
The CpW(CO) 3 (η 1 -CH 2 C=CR) (R = Me 1, Ph 2) complexes were treated with triflic acid (2.0 equiv) in cold dichloromethane (-78°C), and after a long period to the mixture was added water or RNH 2 to give good yields of carbonylation products CpW(CO) 2 (η 1 ,η 2 -CH 2 -CHCHR-Y-CO-) (R = Me, Ph; Y = RN, O). These products were fully characterized by appropriate physical methods including single-crystal X-ray diffraction. If a chiral amine such as (R)-methylbenzylamine was used in the reaction, two optically active isomers in equal proportions were obtained and further separated on a silica column. In the case of (C 5 Me 5 )W(CO) 3 (η 1 -CH 2 C=CPh) (9), its reactions with triflic acid and water in the same reaction sequence produce (C 5 Me 5 )W(CO) 2 (η 1 ,η 2 -CH 2 CHCHPh-O-CO-) as two diastereomers which undergo mutual exchange according to variable-temperature 1 H NMR spectroscopy.