title: Facile regio- and stereoselective hydrometalation of alkynes with a combination of carboxylic acids and group 10 transition metal complexes: selective hydrogenation of alkynes with formic acid.
abstract: A facile, highly stereo- and regioselective hydrometalation of alkynes generating alkenylmetal complex is disclosed for the first time from a reaction of alkyne, carboxylic acid, and a zerovalent group 10 transition metal complex M(PEt(3))(4) (M = Ni, Pd, Pt). A mechanistic study showed that the hydrometalation does not proceed via the reaction of alkyne with a hydridometal generated by the protonation of a carboxylic acid with Pt(PEt(3))(4), but proceeds via a reaction of an alkyne coordinate metal complex with the acid. This finding clarifies the long proposed reaction mechanism that operates via the generation of an alkenylpalladium intermediate and subsequent transformation of this complex in a variety of reactions catalyzed by a combination of Brϕnsted acid and Pd(0) complex. This finding also leads to the disclosure of an unprecedented reduction of alkynes with formic acid that can selectively produce cis-, trans-alkenes and alkanes by slightly tuning the conditions.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Ruwei
authors.initials: R
authors.lastname: Shen
authors.forename: Tieqiao
authors.initials: T
authors.lastname: Chen
authors.forename: Yalei
authors.initials: Y
authors.lastname: Zhao
authors.forename: Renhua
authors.initials: R
authors.lastname: Qiu
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Zhou
authors.forename: Shuangfeng
authors.initials: S
authors.lastname: Yin
authors.forename: Xiangbo
authors.initials: X
authors.lastname: Wang
authors.forename: Midori
authors.initials: M
authors.lastname: Goto
authors.forename: Li-Biao
authors.initials: LB
authors.lastname: Han