title: Site-Selective Alkenylation of δ-C(sp(3))-H Bonds with Alkynes via a Six-Membered Palladacycle.
abstract: Most chelation-assisted aliphatic C-H activation proceeds through a kinetically favored five-membered cyclometalated intermediate. Here, we report the first site-selective alkenylation of δ-C(sp(3))-H in the presence of more accessible γ-C(sp(3))-H bonds via a kinetically less favored six-membered palladacycle. A wide range of functional groups are tolerated, and the unique protocol can be applied to the synthesis of chiral piperidines. Moreover, mechanistic insights have been conducted to elucidate the origin of the unusual site-selectivity.
authors.affiliation: Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Jing-Wen
authors.initials: JW
authors.lastname: Xu
authors.affiliation: Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Zhuo-Zhuo
authors.initials: ZZ
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Wei-Hao
authors.initials: WH
authors.lastname: Rao
authors.affiliation: Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Bing-Feng
authors.initials: BF
authors.lastname: Shi