Reactions of tungsten and molybdenum propargyl complexes with Co2(CO)8, Co4(CO)12, and Cp2Mo2(CO)4. A crossover study of formation of

Article abstract of DOI:10.1016/0022-328X(90)85103-6

The nature of the protonation reaction of (M = Mo, W; R = Me, Ph, p-MeC6H4) (2) (obtained from (CO)3CpMCH2C<*>CR (1) and Co2(CO)8) to give (3) was further investigated by a crossover experiment.Thus, reaction of an equimolar mixture of 2b (M = W, Cp = η⁵-C5H5, R = Ph) and 2e ( M = W, Cp = η⁵-C5H4Me; R = p-MeC6H4) with CF3COOH affords only 3b (same M, Cp, and R as 2b) and 3e (same M, Cp, and R as 2e) to show an intramolecular nature of this transformation.Reaction of (CO)3CpWCH2C<*>CPh (1b) with Co4(CO)12 was also examined and found to yield 2b exclusively.Treatment of 1 with Cp2Mo2(CO)4 at 0-5 deg C provides thermally sensitive compounds, possibly (5), which decompose at room temperature to give Cp2Mo2(CO)6 as the only isolated product.