Total Synthesis of (−)-Gardmultimine A
Peiqi Chen, Hesi Yang, Hao Zhang, Wei Chen, Zheng Zhang, Jing Zhang, Huilin Li, Xiaolei Wang, Xingang Xie, Xuegong She
Abstract
The first total synthesis of Gardneria oxindole alkaloid (−)-gardmultimine A has been achieved in 19 steps from d-tryptophan in a fully stereocontrolled manner. This synthesis features (1) an Ir-catalyzed regioselective C–H borylation/oxidation sequence to introduce the C12 methoxyl group, (2) a stereocontrolled oxidative rearrangement of indole to construct the spirooxindole motif, and (3) an Au(I)-catalyzed transannular Conia-ene-type 6-exo-dig cyclization to establish the azabicyclo[2.2.2]octane skeleton and the exocyclic E-alkene with exclusive stereoselectivity.
Topics & Concepts
ChemistryOxindoleRegioselectivityStereoselectivityBorylationStereochemistryTotal synthesisIndole testAlkeneIndole alkaloidOctaneEne reactionCatalysisOrganic chemistryAlkylArylCatalytic C–H Functionalization MethodsAlkaloids: synthesis and pharmacologyMarine Sponges and Natural Products