Synthesis, characterization and C-H activation reactivity of bis(ethylene)boratabenzene rhodium complexes

Reaction of Li[C5H5B-Ph] with [RhCl(C2H4)(2)](2) gives [C5H5B-Ph]Rh(C2H4)(2 ) 1 in 91% yield; similarly, Li[C5H5B-NMe2] with [RhCl(C2H4)(2)](2) gives [ C5H5B-NMe2]Rh(C2H4)(2) 2 in 85% yield; single crystal X-ray analysis studie s of 1 and 2 show a molecular geometry analogous to those of the Cp and Cp* complexes; the use of 1 and 2 in promoting alkane boration was evaluated a gainst the activity of Cp*Rh(C2H4)(2) 3; the boratabenzene complexes 1 and 2 show faster initiation, but yield less thermally stable catalysts than 3.