Chemistry of Rh-N,S heterocyclic carbene complexes

Chloro-rhodaboratrane [(Cp∗Rh)(L2)BCl] 4 has been synthesized from rhodium N,S-heterocyclic carbene complex [(Cp∗Rh)(L2)(1-benzothiazol-2-ylidene)], 1, (L = C7H4NS2) and borane reagent BHCl2.SMe2. The Rh-B bond in 4 is buttressed between two benzothiazolyl units in [3.3.0] fashion. The presence of B-Cl bond allowed us to explore the chemistry of boratrane 4 at the boron centre. The reaction of ethynylmagnesium bromide with 4 yielded η1-vinyl complex [Cp∗RhBr(C2H2)L] 5, containing a five membered metallaheterocycle. In an objective to abstract the chloride, alike borylene synthesis from haloboryl, we performed the reaction of 4 with NaBArF4 that resulted the thiolato bridged bimetallic compound [Cp∗Rh(μ-L)3RhCp∗][BArF4] 6 (ArF: C6H3(CF3)2-3,5).