REACTION OF RUH2(PME3)4 WITH BENZALDEHYDE - FORMATION OF NOVEL OXAMETALLACYCLE AND METALLACYCLOKETONE COMPLEXES VIA C-H BOND ACTIVATION OF ALDEHYDE

The PMe3-coordinated ruthenium dihydride complex RuH2(PMe3)4 (1) react ed with PhCHO in toluene at -20-degrees-C to give an oxaruthenacycle c omplex (2) and 1 equivalent of PhCH2OH. The same reaction carried out at elevated temperatures, on the other hand, afforded a ruthenacycloke tone complex (3). Complexes 2 and 3 were characterized by means of IR and NMR spectroscopy and elemental analysis. An X-ray diffraction stud y revealed that complex 2 has an oxametallacycle structure associated with benzyl alcohol by a hydrogen bond. Crystal data for 2: orthohombi c, space group Pnb2(1), a = 13.580(1) angstrom, b = 18.220(2) angstrom , c = 12.540(1) angstrom, V = 3102.7(5) angstrom3, Z = 4.