Reactivity of 3,3,3-Trifluoropropyne at Rhodium Complexes: Development of Hydroboration Reactions

The rhodium compounds [Rh(C CCF3)(PEt3)(3)] (2), fac-[RhH(C CCF3)(2)(PEt3)(3)] (3), and fac-[Rh{(E)-CH=CHCF3}(C CCF3)(2)(PEt3)(3)] (4) were synthesized by reactions of the rhodium(I) complexes [Rh(H)(PEt3)(3)] (1) and [Rh(Bpin)(PEt3)(3)] (5, HBpin=pinacolborane) with the alkyne 3,3,3-trifluoropropyne. Reactivity studies of [Rh(C CCF3)(PEt3)(3)] (2) were performed with CO and (CO)-C-13 to form [Rh(C CCF3)(CO)(PEt3)(3)] (7) and subsequently trans-[Rh(C CCF3)(CO)(PEt3)(2)](8) as well as the labeled derivatives. Using 1-4 as catalysts, hydroboration reactions selectively afforded borylated building blocks.