(2-chloro-2-nitroethenyl)benzenes as synthons: a general method for the preparation of 2,3-dihydro- 2-nitro-3-phenyl-4H-furo [3,2-c] [1]benzopyran-4-ones and 3-phenyl-4H-furo[3,2-c][1]benzopyran-4-ones
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.
Efficient and mild synthesis of functionalized 2,3-dihydrofuran derivatives via domino reaction in water
作者:Jian-Wu Xie、Ping Li、Ting Wang、Fei-Ting Zhou
DOI:10.1016/j.tetlet.2011.02.093
日期:2011.5
An efficient and mild method for the synthesis of functionalized tricyclic 2,3-dihydrofurans, bicyclic 2,3-dihydrofurans, and other tetrasubstituted 2,3-dihydrofurans by dominoreaction of 1,3-dicarbonyl compounds and α-bromonitroalkenes with a large substrate scope and excellent diastereoselectivity (only trans isomers) in moderate to excellent yield (up to 96%) has been reported.
The asymmetric domino Michael-SN2 reaction of various 1,3-dicarbonyl compounds to α-bromonitroalkenes is described for the first time, employing readily available cinchona-derived bifunctionalthioureas as organocatalysts. The novel transformations were highly regio-, chemo-, diastereo-, and enantioselective, which simultaneously gave the chiral tricyclic 2,3-dihydrofurans, bicyclic 2,3-dihydrofurans