Chauhan Pankaj, Mahajan Suruchi, Raabe Gerhard, Enders Dieter
Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
Chem Commun (Camb). 2015 Feb 11;51(12):2270-2. doi: 10.1039/c4cc09730k.
An unprecedented stereoselective organocatalytic one-pot 1,4-/1,6-/1,2-addition sequence between β-dicarbonyl compounds, β-nitroalkenes and 4-nitro-5-styrylisoxazoles sequentially catalyzed by low loading of a squaramide catalyst and an achiral base has been developed. The protocol opens an efficient entry to isoxazole bearing cyclohexanes with six consecutive stereogenic centers including one tetrasubstituted carbon in good yields and excellent diastereo- and enantioselectivities.
已开发出一种前所未有的立体选择性有机催化一锅法反应,在低负载量的方酰胺催化剂和非手性碱的依次催化下,β-二羰基化合物、β-硝基烯烃和4-硝基-5-苯乙烯基异恶唑之间依次进行1,4-/1,6-/1,2-加成反应。该方法为合成带有环己烷的异恶唑提供了一条有效途径,产物具有六个连续的立体中心,包括一个四取代碳,产率良好,非对映选择性和对映选择性优异。