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 13 CO 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.