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-1 H -1,2-azaborol-3-yllithium reagents ( 1c, 1d, and 1e ). The reaction of 1e with Py 3 Mo(CO) 3 and BF 3 ·OEt 2 affords Mo(CO) 3 complex 5e, while the reaction of 1c with Cr(CH 3 CN) 3 (CO) 3 affords Cr(CO) 3 complex 6c . X-ray structures of 5e and 6c show that the metals are η 6 -bound to the 1,2-dihydro-1,2-azaborine rings.