Highly diastereoselective entry to chiral oxindole-based β-amino boronic acids and spiro derivatives?

Organic & Biomolecular Chemistry Pub Date: 2021-08-05 DOI: 10.1039/D1OB01303C

Abstract

We here describe the first Cu-catalysed, diastereoselective 1,2-addition of 1,1-diborylmethane to chiral ketimines for the synthesis of quaternary stereocenters and spiro compounds. The method provides easy access to a range of chiral, highly functionalized compounds, namely oxindole-based β,β′-disubstituted β-amino boronates, boron-containing peptidomimetics and six-, seven-membered spirocyclic hemiboronic esters. Such unprecedented compounds are mostly obtained in high yields and easily isolated as single diastereoisomers, paving the way to a more intense exploitation of boron-containing compounds in diversity-oriented chemistry and drug-discovery programs. Concerning stereochemistry, the application of Ellman's auxiliary strategy allows in principle to access both steric series of target compounds.

Graphical abstract: Highly diastereoselective entry to chiral oxindole-based β-amino boronic acids and spiro derivatives
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