OXYGEN-ATOM TRANSFER FROM NITROUS-OXIDE TO AN ORGANONICKEL(II) PHOSPHINE COMPLEX - SYNTHESES AND REACTIONS OF NEW NICKEL(II) ARYLOXIDES AND THE CRYSTAL-STRUCTURE OF (ME(2)PCH(2)CH(2)PME(2))NI(O-O-C(6)H(4)CME(2)CH(2))

Reaction of (PMe(3))(2)Ni(CH(2)CMe(2)-o-C6H4) (1) with N2O gives the oxametallacycle [(PMe(3))Ni(O-o-C(6)H(4)CMe(2)CH(2))](2) (2) and O=PMe(3). Dimeric 2 reacts with CO to give the benzopyran CH2- CMe(2)-o-C6H4OC(O) (3) and with. HCl to give 2-tert-butylphenol. The chelating ligands 2,2'bipyridine (bipy), 1,10-phenanthroline (phen), and 1,2-bis(dimethylphosphino)ethane (dmpe) I react with 2 to afford the monomeric aryloxide complexes (bipy)Ni(O-o-C(6)H(4)CMe(2)CH(2)) (4), (phen)Ni(O-o-C(6)H(4)CMe(2)CH(2)) (5), and (dmpe)Ni(O-o-C(6)H(4)CMe(2)CH(2)) (6), respectively. Reaction of 4 or 5 with CO affords good yields of the lactone 3. Treatment of 5 with I-2 induces formal O,C-reductive elimination, giving 4,4-dimethyl-3,4-dihydrocoumarin, O-o-C(6)H(4)CMe(2)CH(2)- (9), in good yield. 6 has been characterized by single-crystal X-ray diffraction. 6 crystallizes from pentane solution in the monaclinic space group P2(1)/n with a = 9.206(2) Angstrom, b = 12.685(3) Angstrom, c = 15.998(3) Angstrom, beta = 90.33(3)degrees, and Z = 4. The least-squares refinement converged to R(F) = 4.04% and R(wF) = 4.89% for the 1989 unique data with F-0 > 4.5 sigma(F-0).