REACTIONS OF RHENIUM HALIDE-COMPLEXES (ETA-5-C5H5)RE(NO)(PPH3)(X) AND ORGANOCOPPER NUCLEOPHILES - NEW ROUTES TO RACEMIC AND OPTICALLY-ACTIVE HYDROCARBYL COMPLEXES (ETA-5-C5H5)RE(NO)(PPH3)(R)

Reactions of (eta5-C5H5)Re(NO)(PPh3)(I) (1c) and (+)-(R)-1c with CuCH3 (THF, 0 to 25-degrees-C), LiCu(CH3)2 (THF, -80 to 25-degrees-C), CUC6H5 (THF, 0 to 25-degrees-C), and CUC=C6H5 (pyridine, reflux) give the corresponding hydrocarbyl complexes (eta5-C5H5)Re(NO)(PPh3)(R) in 99-68% yields and >98-83% ee (retention at rhenium). For (eta5-C5H5)Re(NO)(PPh3)(CH3) (2), the optical purity depends markedly upon the copper reagent and preparation method. Reaction of (+)-(S)-2 with HBF4.OEt2 and then C6H5C=CH in chlorobenzene yields (-)-(R)-[(eta5-C5H5)Re(NO)(PPh3)(HC=CC6H5)]+BF4- (75%), which upon treatment with K+ t-BuO- gives an authentic sample Of (+)-(S)-(eta5-C5H5)Re(NO)(PPh3)(C=CC6H5) (85%).