A Chiral Alkyltris(pyrazolyl)borate Ligand:  Synthesis of [(Ipc)B(pz)3Mn(CO)3] and [(Ipc)B(pz)3Ru(p-cymene)]PF6 (Ipc = Isopinocampheyl)

The application of the reagent (Ipc)BCl2 (Ipc = isopinocampheyl) in the synthesis of a new tris(pyrazolyl)borate ligand having an Ipc substituent on boron is described. The sodium salt is a convenient precursor for the preparation of the complexes {(Ipc)tris(pyrazolyl)borato}tricarbonylmanganese and [{(Ipc)tris(pyrazolyl)borato}(p-cymene)ruthenium]+, whose X-ray crystal structures are reported. While little distortion of the B(pz)3M unit is observed in these complexes, steric interaction between the Ipc group and the 3-positions of the pyrazolyl rings is noted to lead to distortion of the angles around the B−C bond.