53356-64-2Relevant academic research and scientific papers
Alkine und Cumulene, XV. Ueber die Photodimerisierung konjugierter Enine
Eisenhuth, Ludwig,Siegel, Herbert,Hopf, Henning
, p. 3772 - 3788 (2007/10/02)
On irradiation in the presence of triplet sensitizers having a triplet energy >250 KJ/mol, vinylacetylene (1a) dimerizes to cis- and trans-1,2-diethynylcyclobutane (cis- and trans-2) as well as minor amounts of 4-ethynyl-1-vinylcyclobutene (3).The effect of substituents on the course of the reaction is investigated: whereas alkyl, vinyl, and phenyl substituents, respectively, in the 4-position of 1a do not influence the photoaddition, 2-substituted enynes yield the corresponding cyclobutanes in poor yields only.Finally, 1-substituted vinylacetylenes (besides the substituents mentioned above the influence of ethynyl, chloro, and methoxy groups has been investigated) do not provide photodimers; they are cis-trans-isomerized instead.The mechanism of the photoaddition is discussed.
