title: Copper Catalysis for Synthesizing Main-Group Organometallics Containing B, Sn or Si.
abstract: A copper complex has proven to be a potent catalyst for forming a C-B bond via diborylation of arynes and alkynes, affording vic-diborylarenes and vic-diborylalkenes with high efficiency. A boryl-substituted organocopper species, which is intermediately generated in the diborylation, has been found to be captured by a tin or a carbon electrophile, leading to three-component borylstannylation or carboboration, in which C-B and C-Sn (or C) bonds are constructed simultaneously. Furthermore, reducing the Lewis acidity of the boron center with 1,8-diaminonaphthalene decisively alters the regiochemical behavior of the borylcopper species, enabling the installation of a boryl moiety to occur at an internal carbon of terminal alkynes in borylstannylation and protoboration. Copper catalysis for C-Sn and C-Si bond-forming processes via distannylation, hydrostannylation and silylstannylation, as well as silver catalysis for a C-B bond-forming reaction, is also described.
authors.affiliation: Department of Applied Chemistry Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, 739-8527, Japan.|ACT-C Japan Science and Technology Agency, Higashi-Hiroshima, 739-8527, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Yoshida
keywords: boron; copper; metalation; silicon; tin