Photodimerization of fumaric or several γ-form trans-cinnamic acids proceeded successfully in the solidstate through amine salt formation with ammonia or some aromatic heterocyclic amines (especially, imidazole). It appears that this success is due to a small size or a planar structure of the amine. A layered or a channel-type clathrate crystal structure was revealed, respectively.
Donor–acceptor fluorophores as efficient energy transfer photocatalysts for [2 + 2] photodimerization
作者:Qing-An Wu、Feng Chen、Chen-Chao Ren、Xue-Fen Liu、Hao Chen、Liang-Xuan Xu、Xiao-Cong Yu、Shu-Ping Luo
DOI:10.1039/c9ob02735a
日期:——
Mild [2 + 2] photodimerization of enone substrates was induced by donor-acceptor fluorophores. Enone substrates were activated efficiently for anti-head to head dimerizations with a high yield (up to 83%) and high selectivity. The adjustable excited state potential also allows donor-acceptor fluorophores to be used for isomerization of the above substrates, confirming the potential of donor-acceptor
Template-Directed Photochemical Homodimerization and Heterodimerization Reactions of Cinnamic Acids
作者:Bilge Banu Yagci、Yunus Zorlu、Yunus Emre Türkmen
DOI:10.1021/acs.joc.1c01534
日期:2021.9.17
method for the selective photochemical homo- and heterodimerization of cinnamic acid derivatives with the use of commercially available 1,8-dihydroxynaphthalene as a covalent template. A variety of symmetrical and unsymmetrical β-truxinic acids were obtained in high yields and as single diastereomers. The use of a template not only provides the alignment of the two olefins with suitable proximity (<4
Templating Photodimerization of <i>trans</i>-Cinnamic Acids with Cucurbit[8]uril and γ-Cyclodextrin
作者:Mahesh Pattabiraman、Arunkumar Natarajan、Lakshmi S. Kaanumalle、V. Ramamurthy
DOI:10.1021/ol047866k
日期:2005.2.1
Cucurbit[8]uril and gamma-cyclodextrin are able to align two olefin molecules in a head-head fashion within their large cavities. Excitation of such templated olefins results in syn head-head cyclobutanes in nearly quantitative yields. The methodology revealed here works with transcinnamic acids that do not dimerize either in solution or in the solid state and with the ones that yield only anti head-tail dimer in the solid state.
Structured self-aggregates of 4-methoxy-(E)-cinnamic acid at the air/solution interface as detected by 2.pi. + 2.pi. photodimerization and their role in the control of crystal polymorphism