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Transition-Metal-Free Decarboxylative Propargylic Substitution/Cyclization with either Azolium Enolates or Acyl
Shenci Lu1, Jun-Yang Ong1,2, Si Bei Poh1
1Department of Chemistry, National University of Singapore (NUS), 3 Science Drive 3, Singapore, 117543, Singapore.
Abstract:
Presented herein is an unprecedented transition-metal-free propargylic substitution reaction with either azolium enolates or acyl anions, which are generated from aldehydes under N-heterocyclic carbene catalysis. This new catalytic activation operates on readily available cyclic propargylic carbamates through decarboxylation, and generates reactive allene intermediates that can undergo divergent cyclization pathways to deliver skeletally diverse polycyclic compounds with high levels of efficiency and excellent enantioselectivities.
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