title: A Mild and Ligand-Free Ni-Catalyzed Silylation via C-OMe Cleavage.
abstract: Metal-catalyzed transformations that forge carbon-heteroatom bonds are of central importance in organic synthesis. Despite the formidable potential of aryl methyl ethers as coupling partners, the scarcity of metal-catalyzed C-heteroatom bond formations via C-OMe cleavage is striking, with isolated precedents requiring specialized, yet expensive, ligands, high temperatures, and π-extended backbones. We report an unprecedented catalytic ipso-silylation of aryl methyl ethers under mild conditions and without recourse to external ligands. The method is distinguished by its wide scope, which includes the use of benzyl methyl ethers, vinyl methyl ethers, and unbiased anisole derivatives, thus representing a significant step forward for designing new C-heteroatom bond formations via C-OMe scission. Applications of this transformation in orthogonal silylation techniques as well as in further derivatizations are also described. Preliminary mechanistic experiments suggest the intermediacy of Ni(0)-ate complexes, leaving some doubt that a canonical catalytic cycle consisting of an initial oxidative addition of the C-OMe bond to Ni(0) species comes into play.
authors.affiliation: Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology , Av. Països Catalans 16, 43007 Tarragona, Spain.
authors.forename: Cayetana
authors.initials: C
authors.lastname: Zarate
authors.affiliation: Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology , Av. Països Catalans 16, 43007 Tarragona, Spain.
authors.forename: Masaki
authors.initials: M
authors.lastname: Nakajima
authors.affiliation: Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology , Av. Països Catalans 16, 43007 Tarragona, Spain.|ICREA , Passeig Lluïs Companys, 23, 08010 Barcelona, Spain.
authors.forename: Ruben
authors.identifier: 0000-0002-2543-0221
authors.initials: R
authors.lastname: Martin