Paternò–Büchi reaction

The Paternò–Büchi reaction, named after Emanuele Paternò and George Büchi, who established its basic utility and form,[1][2] is a photochemical reaction, specifically a 2+2 photocycloaddition, which forms four-membered oxetane rings from an excited carbonyl and reacting with an alkene.[3] With substrates benzaldehyde and 2-methyl-2-butene the reaction product is a mixture of structural isomers: Another substrate set is benzaldehyde and furan[4] or heteroaromatic ketones and fluorinated alkenes.[5] The alternative strategy for the above reaction is called the Transposed Paternò−Büchi reaction.
Here an electronically excited carbonyl group is added to a ground state olefin yielding an oxetane .
Emanuele PaternòGeorge BüchiRing forming reactionphotochemical reaction2+2 photocycloadditionoxetanecarbonylalkeneolefinbenzaldehyde2-methyl-2-butenestructural isomersTransposed Paternò−Büchi reactionAza Paternò−Büchi reactionEnone–alkene cycloadditionscyclobuteneGazz. Chim. Ital.Journal of the American Chemical SocietyLu Shin WongJournal of Chemical Education