Photosensitised regioselective [2+2]-cycloaddition of cinnamates and related alkenes
作者:Santosh K. Pagire、Asik Hossain、Lukas Traub、Sabine Kerres、Oliver Reiser
DOI:10.1039/c7cc06710k
日期:——
An efficient method for the synthesis of substituted cyclobutanes from cinnamates, chalcones, and styrenes has been developed utilizing a visible-light triplet sensitisation mode. This reaction provides a diverse range of substituted cyclobutanes in high yields under mild conditions without the need of external additives. Good regioselectivity is obtained due to strong π–π-stacking of arene moieties
polyhydroxylated azepanes. Polyheterocyclic scaffolds were prepared by intramolecular aza-[4+3] cycloadditionreactions of aza-oxyallylic cations with cyclic dienes. The aza-oxyallylic cation was generated in situ by the dehydrohalogenation of α-halohydroxamates. The highly functionalized heterocyclic products undergo a variety of reactions that provide useful scaffolds for target-directed synthesis, including