[(PhBP3)Cu(PPh3)] as a surrogate of TpxCuL in homogeneous catalysis (PhBP3 = PhB(CH2PPh2)3; Tpx = hydrotrispyrazolylborate)

Abstract

The novel complexes [(PhBP3)Cu(L)] (PhBP3 = PhB(CH2PPh2)3, L = PPh3, 1; L = tetrahydrofuran, 2) have been synthesized and spectroscopically and, in the case of 1, structurally characterized. Both complexes undergo dissociation of the PPh3 or THF ligand in solution to deliver the (PhBP3)Cu unit, similar in geometry to and isoelectronic with TpxCu (Tpx = trispyrazolylborate ligand). A complete study of the catalytic properties of 1 has shown that it can be considered as a surrogate of TpxCu. The study includes (a) olefin cyclopropanation, cyclopropenation, aziridination, halocarbon addition, and radical polymerization, (b) X–H (X = O, N) functionalization by carbene insertion, and (c) furan conversion into dihydropyridines. Since the observed activity is quite comparable to that already described for TpxCu complexes, this new catalytic system could become an alternative to the latter.