New carbonylation reaction of tungsten-propargyl compounds via protonationat a prolonged period

The CpW(CO)(3)(eta(1)-CH2C equivalent to CR) (R = Me 1, Ph 2) complexes wer e treated with triflic acid (2.0 equiv) in cold dichloromethane (-78 degree s C), and after a long period to the mixture was added water or RNH2 to giv e good yields of carbonylation products CpW(CO)(2)(eta(1),eta(2)-CH2-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 se parated on a silica column. In the case of (C5Me5)W(CO)(3)(eta(1)-CH2C equi valent to CPh) (9), its reactions with triflic acid and water in the same r eaction sequence produce (C5Me5)W(CO)(2)(eta(1),eta(2)-CH2CHCHPh-O-CO-) as two diastereomers which undergo mutual exchange according to variable-tempe rature H-1 NMR spectroscopy.