REACTION OF AMINOCARBENE COMPLEXES OF CHROMIUM AND TUNGSTEN .6. REARRANGEMENTS OF AND INSERTIONS OF ALKYNES INTO AZIRIDINYLCARBENE COMPLEXES

Pentacarbonyl[(2-methylaziridinyl)(methyl)carbene]chromium(0) (2a) reacts with LiBu followed by H2O to regenerate the starting carbene complex. Treatment of the same reaction mixture with D2O leads to the perdeuteromethyl carbene complex 2D(3). However, addition of CH3I instead of D2O gives pentacarbonyl(N-methyl-2-aza-3-methylcyclopentylidene)chromium(0) (28) by ring opening followed by alkylation at nitrogen. The aziridinylcarbene complexes [(CO)(5)M = C(NCH(CH3)CH2)R(1)(M = Cr, R(1) = Me, 2a, R(1) = Ph, 2b, R(1) = cyclopropyl, 2c react with diphenylacetylene or phenylpropyne) to give 30a-c, 33 and 34 via double alkyne and single CO insertions. However, complex 20 (M = W, R(1) = Me) gave only trace amounts of the expected complex 30d. Treatment of 30a with pyridine led to the metal-free derivative 31. Complex 30b (R(1) = Ph) was fully characterized by X-ray diffraction.