Comparative reactivities of two isoelectronic transition-metal hydrides with transition-metal carbonyls and alkyls

Abstract

The two isoelectronic hydrides PPN/sup +/CpV(CO)/sub 3/H/sup -/ (1) and -CpMo(CO)/sub 3/H (2) react with a variety of metal carbonyls and alkyls. Treatment of Fe(CO)/sub 5/, Cr(CO)/sub 6/, (CH/sub 3/C/sub 5/H/sub 4/)V(CO)/sub 4/, CH/sub 3/Re(CO)/sub 5/, and (CH/sub 3/CO)Re(CO)/sub 5/ with 1 produces HFe(CO)/sub 4//sup -/, HCr(CO)/sub 5//sup -/, (CH/sub 3/C/sub 5/H/sub 4/)V(CO)/sub 3/H/sup -/, (H)(CH/sub 3/)Re(CO)/sub 4//sup -/, and (H)(CH/sub 3/CO)Re(CO)/sub 4//sup -/, respectively, and CpV(CO)/sub 4/ (3). l also catalyzes ligand substitution reactions in 3 and CpFe(CO)(PPh/sub 3/)(COCH/sub 3/). In comparison 2 reacts only with CH/sub 3/Mn(CO)/sub 5/ and CpMo(CO)/sub 3/R(R = CH/sub 3/, C/sub 2/H/sub 5/, CH/sub 2/C/sub 6/H/sub 5/) producing aldehydes and the dimers (CpMo(CO)/sub 3/)/sub 2/ (4a) and (CpMo(CO)/sub 2/)/sub 2/ (5a). Reaction of 2 with ethylene produces ethane and diethyl ketone. l is proposed to react by an electron-transfer mechanism, whereas 2 is proposed to react by hydrogen transfer to a vacant coordination site. The relationship of the molybdenum hydride/alkyl reaction to the final step in hydroformylation (oxo process) is discussed.