title: Cyclobutene formation in PtCl2-catalyzed cycloisomerizations of heteroatom-tethered 1,6-enynes.
abstract: Aza(oxa)bicyclo[3.2.0]heptenes are accessed through the PtCl2 -catalyzed cycloisomerizations of heteroatom-tethered 1,6-enynes featuring a terminal alkyne and amide as the solvent. It is shown that the weak coordinating properties of the solvent and alkyl substituent(s) at the propargylic carbon atom favor the formation of cyclobutenes instead of other possible cycloisomerization products such as 1,3-diene derivatives or cyclopropane-fused heterocycles.
authors.affiliation: Aix-Marseille Université, Centrale Marseille, CNRS, ISm2, UMR 7313, 13397 Marseille (France).
authors.forename: Zhenjie
authors.initials: Z
authors.lastname: Ni
authors.forename: Laurent
authors.initials: L
authors.lastname: Giordano
authors.forename: Alphonse
authors.initials: A
authors.lastname: Tenaglia
keywords: cyclobutenes; cycloisomerization; enynes; platinum; small ring systems; solvent effects