A catalyticenantioselectivesynthesis of dihydrofurans has been developed. 1,3-Dicarbonyl derivatives react with (E)-β,β-bromonitrostyrenes in the presence of a chiral bifunctional thiourea catalyst providing mild and efficient access to diverse polysubstituted dihydrofurans in good yields and enantioselectivities.
An asymmetric formal one‐pot reaction of 1,3‐dicarbonyl derivatives with non‐bromo‐substituted nitroolefins has been developed by merging a chiral bifunctional organocatalyst with molecular iodine.
organocatalyst to catalyze the asymmetric domino Michael–alkylation reaction between cyclohexane‐1,3‐dione derivatives and bromonitrostyrenes. For dimedone, the corresponding bicyclic 2,3‐dihydrofurans with two stereocenters were obtained in up to 99 % yield with 95:5 d.r. and 96 % ee. For prochiral 5‐monosubstituted cyclohexane‐1,3‐diones, the desymmetrization reaction provided the bicyclic 2,3‐dihydrofurans