32178-65-7Relevant academic research and scientific papers
Intramolecular [2+2] Photocycloaddition of Cyclic Enones: Selectivity Control by Lewis Acids and Mechanistic Implications
Poplata, Saner,Bauer, Andreas,Storch, Golo,Bach, Thorsten
supporting information, p. 8135 - 8148 (2019/05/29)
The intramolecular [2+2] photocycloaddition of 3-alkenyl-2-cycloalkenones was performed in an enantioselective fashion (nine representative examples, 54–86 % yield, 76–96 % ee) upon irradiation at λ=366 nm in the presence of an AlBr3-activated oxazaborolidine as the Lewis acid. An extensive screening of proline-derived oxazaborolidines showed that the enantioface differentiation depends strongly on the nature of the aryl group at the 3-position of the heterocycle. DFT calculations of the Lewis acid–substrate complex indicate that attractive dispersion forces may be responsible for a change of the binding mode. The catalytic [2+2] photocycloaddition was shown to proceed on the triplet hypersurface with a quantum yield of 0.05. The positive effect of Lewis acids on the outcome of a given intramolecular [2+2] photocycloaddition was illustrated by optimizing the key step in a concise total synthesis of the sesquiterpene (±)-italicene.
Intramolecular Photochemical Cycloaddition Reactions of 3-(1,5-Dimethylhex-4-enyl)cyclohex-2-enone: Regio- and Stereochemical Aspects
Hoye, Thomas R.,Martin, Steven J.,Peck, David R.
, p. 331 - 337 (2007/10/02)
The intramolecular photocycloaddition reaction of the title enone (1) and its 1-demethyl analogue (2) gives head-to-head , adducts containing cyclopentacyclobutabenzen-5(6H)-one skeletons and none of the head-to-tail isomers of the tricycl
