摘要
Indole-based atropisomers are a very important class of axially chiral compounds.However,the atroposelective synthesis of axially chiral 2-arylindole remains largely unexplored.In this study,we report the successful synthesis of atropisomeric 2-arylindoles using direct amination of indoles with p-quinonediimines in the presence of chiral phosphoric acid as a catalyst.Quinonediimine acts as an aminating reagent through formal polarity inversion of imine.The malonate group on the 2-aryl of 2-indoles was found to be essen-tial for high enantioselectivity of the products.This could be due to the additional interaction between the ester group and the cata-lyst,as well as the intramolecular hydrogen bonding.Our findings provide a new strategy for the asymmetric construction of 2-arylindole atropisomers.
基金
support from the National Key R&D Program of China (2022YFA1503703,2021YFF0701604)
the National Natural Science Foundation of China (21825105,22231004,22271135)
Guangdong Innovative Program (2019BT02Y335)
Shenzhen Science and Technology Program (KQTD20210811090112004,JCYJ20210324120205016,JCYJ20210324105005015).