Orthogonal Syntheses of 3.2.0 Bicycles from Enallenes Promoted by Visible Light
journal contributionposted on 05.08.2020, 11:35 by Andrea Serafino, Davide Balestri, Luciano Marchiò, Max Malacria, Etienne Derat, Giovanni Maestri
Enallenes can be readily converted into two families of 3.2.0 (hetero)bicycles with high diastereoselectivities through the combination of visible light with a suitable Ir(III) complex (1 mol %). Two complementary pathways, namely, a photocycloaddition versus a radical chain, can then take place. Both manifolds grant complete regiocontrol of the allene difunctionalization. This is accompanied by an original 1,3-group shift using sulfonyl allenamides that deliver a congested tetrasubstituted headbridging carbon in the corresponding product.