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
Visible light-induced highly selective transformation of olefin to ketone by 2,4,6-triphenylpyrylium cation encapsulated within zeolite Y
作者:Yasuhiro Shiraishi、Naoya Saito、Takayuki Hirai
DOI:10.1039/b515137f
日期:——
2,4,6-Triphenylpyrylium cation encapsulated withinzeolite Y promotes highly selective transformation of olefins to ketones with molecular oxygen, under visible light (lambda > 400 nm) irradiation at room temperature.
carbocyclization of homoallylic alcohols has been developed by using hydrosilanes as reducing reagents to provide a range of 1,2‐disubstituted arylcyclobutanes. The reaction proceeds in a cis‐selective manner with high efficiency under mild conditions. Mechanistic studies, including deuterium scrambling and Hammett studies, and DFT calculations, suggest a dual ring‐closing pathway.
The synthesis of cycloalkanes via anionic coupling reactions
作者:D. H. Richards、N. F. Scilly
DOI:10.1039/j39690002661
日期:——
A number of cycloalkanes have been isolated among the products of the reactions of geminal and vicinal dihalides with dimeric dianions produced from substituted styrenes by the action of lithium. The n.m.r. and mass spectra of the products are reported.
SINGLET-PHOTOSENSITIZED RING-SPLITTING AND ISOMERIZATION REACTIONS OF 1,2-DIPHENYLCYCLOBUTANE BY AROMATIC NITRILES. A POSSIBLE PROBE FOR RELATIONSHIPS BETWEEN REACTIVITIES AND ELECTRONIC NATURE OF EXCIPLEX INTERMEDIATES
The photosensitized reactions of cis-1,2-diphenylcyclobutane by 1,4-dicyanonaphthalene and 9,10-dicyanoanthracene gave styrene, the trans isomer, and 1-phenyltetralin whereas the photosensitization by 1-cyanonaphthalene effected the ring-splitting and cis,trans-isomerization reactions without the formation of 1-phenyltetralin. Similar reactions of the trans isomer were photosensitized by the aromatic