title: Lanthanide-Catalyzed Reversible Alkynyl Exchange by Carbon-Carbon Single-Bond Cleavage Assisted by a Secondary Amino Group.
abstract: Lanthanide-catalyzed alkynyl exchange through C-C single-bond cleavage assisted by a secondary amino group is reported. A lanthanide amido complex is proposed as a key intermediate, which undergoes unprecedented reversible β-alkynyl elimination followed by alkynyl exchange and imine reinsertion. The in situ homo- and cross-dimerization of the liberated alkyne can serve as an additional driving force to shift the metathesis equilibrium to completion. This reaction is formally complementary to conventional alkyne metathesis and allows the selective transformation of internal propargylamines into those bearing different substituents on the alkyne terminus in moderate to excellent yields under operationally simple reaction conditions.
authors: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, P.R. China.
authors: Yinlin
authors: Y
authors: Shao
authors: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, P.R. China.
authors: Fangjun
authors: F
authors: Zhang
authors: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, P.R. China.
authors: Jie
authors: J
authors: Zhang
authors: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, P.R. China. xgzhou@fudan.edu.cn.|State Key Laboratory of Organometallic Chemistry, Shanghai, 200032, P.R. China. xgzhou@fudan.edu.cn.
authors: Xigeng
authors: X
authors: Zhou
keywords: C−C bond cleavage; alkynes; amines; lanthanides; reaction mechanisms