Δ<sup>2</sup>- and Δ<sup>3</sup>-Azaosmetine Complexes as Intermediates in the Stoichiometric Imination of Phenylacetylene with Oximes
作者:Ricardo Castarlenas、Miguel A. Esteruelas、Enrique Oñate
DOI:10.1021/om010005k
日期:2001.5.1
Complexes [Os(E)-CH=CHPh}Cl(=N=CR2)((PPr3)-Pr-i)(2)] [CF3SO3] [CR2 = CMe2 (1), C(CH2)(4)CH2 (2)] react with carbon monoxide to give the Delta (2)1,2-azaosmetine derivatives [OsCl(=CRCH(Ph)N=CR2}(CO)((PPr3)-Pr-i)(2)][CF3SO3] [CR2 = CMe2 (3), C(CH2)(4)CH2 (4)], as a result of the coordination of carbon monoxide to the osmium atoms of 1 and 2 and the carbon-nitrogen coupling between the styryl and azavinylidene ligands. The structure of 3- in the solid state has been determined by an X-ray diffraction study. Complexes 3 and 4 can be deprotonated with MeLi to give the Delta (3)-1,2-azaosmetine compounds OsCH=C(Ph)N= CR2}Cl(CO)((PPr3)-Pr-i)(2) [CR2 = CMe2 (5), C(CH2)(4)CH2 (6)], which react with molecular hydrogen to afford the 2aza-1,3-butadienes CH2=C(Ph)N=CR2 [CR2 = CMe2 (7), C(CH2)(4)CH2 (8)] and OsH2(eta (2)-H-2)(CO)((PPr3)-Pr-i)(2). The carbonylation of the cations of 3 and 4 leads to [Os(Z)-CH= C(Ph)NH=CR2}Cl(CO)(2)((PPr3)-Pr-i)(2)](+) [CR2 = CMe2 (9), C(CH2)(4)CH2 (CH2)(4)CH2 (10)]. The [BF4](-) salts of 9 and 10 have been obtained by carbonylation of 5 and 6 and subsequent protonation of the resulting eta (1)-azabutadiene intermediates Os(Z)-CH=C(Ph)N=CR2}Cl(CO)(2)((PPr3)-Pr-i)(2) [CR2 = CMe2 (11), C(CH2)(4)CH2 (12)]. The structure of the [BF4](-) salt of 10 in the solid state has also been determined by an X-ray diffraction study.