75697-76-6Relevant articles and documents
Intramolecular Photocycloaddition Reactions of Phenyl-Vinyl Bichromophoric Systems
Gilbert, Andrew,Taylor, Grahame N.
, p. 1761 - 1768 (2007/10/02)
The intramolecular photocycloaddition reactions of several phenyl-vinyl bichromophoric systems are reported. 5-Phenylpent-1-ene and allyl benzyl ether both yielded meta-cycloadducts derived from 1,3- and 2,6-attack of the vinyl group on to the phenyl moiety, whereas 3-phenylpropyl vinyl ether and 2-phenoxybut-1-ene gave products which reflected 1,3- and 2,4-, and 2,4-attack, respectively.In contrast, the maior mode of reaction from phenethyl vinyl ether involved 2,5-cycloaddition and the 1,4-intramolecular cycloadduct structure was assigned to the sole photoisomer of 2-phenoxyethyl vinyl ether.Quantum efficiencies were very variable ranging from 0.005 to 0.11; polymeric materials were formed in all cases and were the major products from the two phenoxy-compounds.The reactions are discussed in terms of previous mechanistic proposals for benzene-ethylene photocycloaddition processes and conformation of the exited-state molecules.
