title: Synthesis of δ- and α-Carbolines via Nickel-Catalyzed [2 + 2 + 2] Cycloaddition of Functionalized Alkyne-Nitriles with Alkynes.
abstract: A new method for the synthesis of δ- and α-carbolines through Ni-catalyzed [2 + 2 + 2] cycloaddition of ynamide-nitriles or alkyne-cyanamides with alkynes has been developed. The catalytic system of NiCl2(DME)/dppp/Zn with a low-cost Ni(II)-precursor was first utilized in Ni-catalyzed [2 + 2 + 2] cycloaddition reactions, and the in situ generated Lewis acid may play an important role for the successful transformation. Not only internal alkynes but also terminal alkynes undergo the desired cycloaddition reactions efficiently to furnish the carboline derivatives with wide diversity and functional group tolerance.
authors.affiliation: State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Lu, Shanghai 200032, People's Republic of China.
authors.forename: Gaonan
authors.initials: G
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Lu, Shanghai 200032, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: You
authors.affiliation: State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Lu, Shanghai 200032, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Gan
authors.affiliation: State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Lu, Shanghai 200032, People's Republic of China.
authors.forename: Yuanhong
authors.identifier: 0000-0003-1153-5695
authors.initials: Y
authors.lastname: Liu