Practical and Scalable Kinetic Resolution of BINOLs Mediated by a Chiral Counterion

Benjamin A Jones; Tudor Balan; John D Jolliffe; Craig D Campbell; Martin D Smith

doi:10.1002/anie.201814381

Practical and Scalable Kinetic Resolution of BINOLs Mediated by a Chiral Counterion

Angew Chem Int Ed Engl. 2019 Mar 26;58(14):4596-4600. doi: 10.1002/anie.201814381. Epub 2019 Mar 5.

Authors

Benjamin A Jones¹, Tudor Balan¹, John D Jolliffe¹, Craig D Campbell¹, Martin D Smith¹

Affiliation

¹ Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.

Abstract

BINOLs are valuable and widely used building blocks, chiral ligands, and catalysts that are effective across a remarkable range of different chemical transformations. Here we demonstrate that an ammonium salt catalyzed kinetic resolution of racemic BINOLs with benzyl tosylate proceeds with s up to 46. This is a scalable and practical process that can be applied across >30 different C₂ - and non-C₂ -symmetric BINOLs. Implementation of this method enables the enantioselective synthesis of a wide range of BINOL derivatives with over 99:1 e.r.

Keywords: BINOL; ammonium; axial chirality; counterion; phase-transfer.

Abstract

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