1,2-Addition versus homoconjugate addition reactions of indoles and electron-rich arenes to alpha-cyclopropyl N-acyliminium ions: synthetic and computational studies
Greg M Ryder, Uta Wille, Anthony C Willis, Stephen G Pyne
Organic & Biomolecular Chemistry | ROYAL SOC CHEMISTRY | Published : 2019
An investigation of the reactivity of α-cyclopropyl N-acyliminium ions towards indoles has resulted in the unprecedented synthesis of 5-cyclopropyl-5-(3-indoyl)pyrrolidin-2-ones via 1,2-addition reactions and, in the case of highly electron deficient indoles and electron rich arenes, spiroheterocycles via sequential homoconjugate and 1,2-addition reactions with often high diastereoselective control at the C-5 quaternary stereocentres. Computational studies provided support for the proposed mechanisms and stereochemical outcome of these reactions, clearly showing that the 1,2-addition pathway is kinetically controlled. In reactions where the 1,2-adduct is destabilised, for example when the ar..View full abstract
Awarded by Australian Research Council
We thank the Australian Research Council (DP130101968) for a PhD scholarship for G. R. and the Universities of Wollongong and Melbourne (High Performance Computing service) for their support.