title: Reactions of [Cu(X)(BPEP-Ph)] (X = PF6, SbF6) with silyl compounds. Cooperative bond activation involving non-coordinating anions.
abstract: Bond activation of silyl compounds, assisted by the cooperative action of non-coordinating anions, is achieved using Cu(I) complexes coordinated with a PNP-pincer type phosphaalkene ligand, [Cu(X)(BPEP-Ph)] (X = PF6 (1a), SbF6 (1b); BPEP-Ph = 2,6-bis[1-phenyl-2-(2,4,6-tri-tert-butylphenyl)-2-phosphaethenyl]pyridine). Complexes 1a and 1b react with Me3SiCN to form Me3SiF and Cu(i) cyanide complexes of the formula [Cu(CN-EF5)(BPEP-Ph)] (E = P (2a), Sb (2b)), in which the CN ligand is associated with the EF5 group arising from EF6(-). Formation of the intermediary isonitrile complex [Cu(CNSiMe3)(BPEP-Ph)](+)SbF6(-) (3b) is confirmed by its isolation. Thus, a two-step reaction process involving coordination of Me3SiCN, followed by nucleophilic attack of SbF6(-) on the silicon atom of 3b is established for the conversion of 1b to 2b. Complex 1b cleaves the H-Si bond of PhMe2SiH as well. The isolation and structural identification of [Cu(BPEP-Ph)](+)BAr(F)4(-) (1c) (BAr(F)4 = B{3,5-(CF3)2C6H3}4) as a rare example of a T-shaped, three-coordinated Cu(i) complex is reported.
authors.affiliation: Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan. yumiko-nakajima@aist.go.jp.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nakajima
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsuchimoto
authors.forename: Yung-Hung
authors.initials: YH
authors.lastname: Chang
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Ozawa