Synthesis of 1,2-dihydro-1,2-azaborines and their conversion to tricarbonyl chromium and molybdenum complexes

1,2-Dihydro-1,2-azaborines (1c, 1d, and 1e) have been prepared by the reaction of the corresponding 2,3-dihydro-1H-1,2-azaborol-3-yllithium reagents (1c, 1d, and 1e). The reaction of le with Py3Mo(CO)(3) and BF3. OEt2 affords MO(CO)3 complex 5e, while the reaction of 1c, with Cr(CH3CN)(3)(CO)(3) affords Cr(CO)3 complex 6c. X-ray structures of 5e and 6c show that the metals are eta (6)-bound to the 1,2-dihydro-1,2-azaborine rings.