Cinchona-based squaramide-catalysed cascade aza-Michael–Michael addition: enantioselective construction of functionalized spirooxindole tetrahydroquinolines
作者:Wen Yang、Da-Ming Du
DOI:10.1039/c3cc44930k
日期:——
An efficient enantioselective cascadeaza-Michael-Michael addition reaction catalysed by a chiral bifunctional tertiary amine-squaramide catalyst has been developed. This cascadereaction proceeded well under mild conditions, furnishing highly functionalized spirooxindole tetrahydroquinolines with three contiguous stereocenters in excellent yields with excellent diastereoselectivities (>25:1 dr) and
Catalyst-free Synthesis of Spiro[indoline-3,1′-pyrazolo[5,1-a]isoquinolines]<i>via</i>Diastereoselective 1,3-dipolar Cycloaddition under Mild Conditions
A highly efficient catalyst‐free1,3‐dipolar cycloaddition reaction of methyleneindolinones and C,N‐cyclic azomethine imines was realized. The reactions afforded a large variety of spirooxindoles in high yields (up to 99%) and excellent diastereoselectivities (dr > 20:1). Furthermore, the configuration of one of the products was determined on the basis of X‐ray structural analysis. Accordingly, a possible