Diboran(4)yl Groups as Ligands to Transition Metals

Reaction of Na[(Cp)Fe(CO) 2 ] and Na[(Cp)W(CO) 3 ] with B 2 (NMe 2 ) 2 Cl 2 yields the first transition metal‐substituted diboranes [Cl(Me 2 N)B–B(NMe 2 )M(Cp)(CO) n ] [M(Cp)(CO) n  Fe(Cp)(CO) 2 , W(Cp)(CO) 3 ] ( 1a, b ). The compounds were characterized in solution by NMR methods and in the crystal by X‐ray structural determination.