Palladium-catalysed asymmetric regioselective hydroamination of dienoates†

Abstract

Electron-deficient dienoates are occasionally utilised in hydrofunctionalisation reactions, and regioselectivity is a common concern. Here we report the palladium-catalysed enantioselective formal 1,4-Michael addition of pyrazoles to δ-aryl-substituted dienoates, proceeding through Pd⁰ π-Lewis base-mediated protonation followed by regioselective asymmetric amination of the resultant π-allylpalladium species. Moreover, an intramolecular 1,5-addition-type reaction is realised under identical conditions by using δ-aryl-functionalised dienoates, affording indoline products enantioselectively.