A Tunable and Enantioselective Hetero-Diels-Alder Reaction Provides Access to Distinct Piperidinoyl Spirooxindoles

Angew Chem Int Ed Engl. 2017 Dec 11;56(50):15945-15949. doi: 10.1002/anie.201708355. Epub 2017 Nov 22.

Abstract

The active complexes of chiral N,N'-dioxide ligands with dysprosium and magnesium salts catalyze the hetero-Diels-Alder reaction between 2-aza-3-silyloxy-butadienes and alkylidene oxindoles to selectively form 3,3'- and 3,4'-piperidinoyl spirooxindoles, respectively, in very high yields and with excellent enantioselectivities. The exo-selective asymmetric cycloaddition successfully regaled the construction of sp3 -rich and highly substituted natural-product-based spirooxindoles supporting many chiral centers, including contiguous all-carbon quaternary centers.

Keywords: asymmetric synthesis; azadienes; cycloaddition; heterocycles; spiro-compounds.

Publication types

  • Research Support, Non-U.S. Gov't