title: Zirconium-mediated multicomponent reactions of 1,3-butadiynes with ylidenemalononitriles to form functionalized 1,8-naphthyridine and cyclopenta[b]pyridine derivatives.
abstract: Zirconocene-mediated multicomponent reactions of 1,3-butadiynes with ylidenemalononitriles in the absence or presence of CuCl have been developed. In the absence of CuCl, 1,3-butadiyne couples with three molecules of ylidenemalononitriles to yield azazirconacycles bearing a hexahydro-1,8-naphthyridine skeleton with high stereoselectivity. In the presence of CuCl, cyclopenta[b]pyridine or cyclopenta[b]quinolin-1-one derivatives are obtained via transmetalation of Zr-C bond to Cu-C bond as the key reaction step. These domino-type reactions proceed with high chemo-, regio- and/or stereoselectivities, and allowing the formation of multiple C-N and C-C bonds in a single operation.
authors.affiliation: State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032 (P. R. China), Fax: (+86) 021-64166128.
authors.forename: Shasha
authors.initials: S
authors.lastname: Yu
authors.forename: Renhong
authors.initials: R
authors.lastname: Sun
authors.forename: Haoyi
authors.initials: H
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Xie
authors.forename: Yuanhong
authors.initials: Y
authors.lastname: Liu
keywords: butadiynes; domino reactions; heterocycles; multicomponent reactions; zirconium