Zhu, BoLee, RichmondLi, JiangtaoYe, XinyiHong, San-NiQiu, ShuaiCoote, MichelleJiang, Zhiyong2020-09-022020-09-021433-7851http://hdl.handle.net/1885/209213We report a synthetic strategy for a chemoselective switch and a diastereo-divergent approach for the asymmetric reaction of 5H-oxazol-4-ones and N-itaconimides catalyzed by l-tert-leucine-derived tertiary amine-urea compounds. The reaction was modulated to harness either tandem conjugate addition-protonation or [4+2] cycloaddition as major product with excellent enantio- and diastereoselectivities. Subjecting the enantio-enriched cycloaddition products to a basic silica gel reagent yields the diastereomer vis-à-vis the product directly obtained under conditions for addition-protonation, thus opening a diastereo-divergent route for creating 1,3-tertiary-hetero-quaternary stereocenters. Quantum chemical studies further provide stereochemical analysis for the [4+2] process and a plausible mechanism for this chemoselective switch is proposed.Z.J. is grateful for the grants from NSFC (grant number21072044), NCET-11-0938 and the Program for Innovative Research Team from the University of Henan Province(14IRTSTHN006). M.L.C.gratefully acknowledges generous allocations of supercomputing time on the National Facility of the National Computational Infrastructure,and financial support from the Australian Research Council.application/pdfen-AU© 2016 Wiley-VCH VerlagGmbH &Co. KGaA,Weinheimchemoselectivitychiralitydensity functional calculationsorganocatalysissynthetic methods2016-01-2210.1002/anie.201507796