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Merging Organocatalysis with 1,2-Boronate Rearrangement: A Lewis Base-Catalyzed Asymmetric Multicomponent Reaction
Hong-Cheng Shen1, Varinder K Aggarwal1
1School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, U.K.
Abstract:
Catalytic asymmetric multicomponent 1,2-boronate rearrangements provide a practical approach for synthesizing highly valuable enantioenriched boronic esters. When applied to alkenyl or heteroaryl boronates, these reactions have relied mainly on transition-metal catalysis. Herein, we present an organocatalytic, Lewis base-catalyzed asymmetric multicomponent 1,2-boronate rearrangement, involving indoles, boronic esters, and Morita-Baylis-Hillman carbonates, leading to enantioenriched, highly substituted indole and indoline derivatives. Using cinchona alkaloid-based catalysts, high selectivity has been achieved, enabling expansion of the chemical space around pharmaceutically relevant indole and indoline derivatives.
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