New borylene complexes of the type [mu-BX{(eta(5)-C5H5Me)Mn(CO)(2)}(2)]: Substitution reactions at the metal-coordinated borylene moiety

The reaction of the air-and water-stable borylene complex [mu-BNMe(2)({eta(5)-C(5)H(4)Me)Mn(CO)(2)}(2)] (1a) with a solution of HCl in Et(2)O affords the corresponding chloroborylene complex [mu-Chloroborylenebis(dicarbonyl(eta(5)-methylcyclopentadienyl)manganese)(Mn-Mn)] (2), This compound easily undergoes further substitution reactions with protic reagents such as primary amines, alcohols and water at the metal coordinated borylene moiety with elimination of HCl, giving new products of the type [mu-BX{(eta(5)-C(5)H(4)Me)Mn(CO)(2)}(2)] (3a, b: X = NHtBu, NHPh; 4a, b: X = OMe, OEt; 5: X = OH). All borylene complexes were isolated as crystalline solids in good yields and characterized by multinuclear NMR methods and IR spectroscopy in solution, In addition, the structure of 4b in the crystalline state was determined by a single-crystal X-ray study.