Stereodivergent Olefination of Enantioenriched Boronic Esters

• Published in: Angewandte Chemie International Edition Vol. 56; no. 3; pp. 786 - 790
• Main Authors: Armstrong, Roly J., García‐Ruiz, Cristina, Myers, Eddie L., Aggarwal, Varinder K.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 16.01.2017; Wiley Subscription Services, Inc; John Wiley and Sons Inc
• Edition: International ed. in English
• Subjects: alkenes; boron; Catalysts; Chemistry; Chemistry, Multidisciplinary; Communication; Communications; Coupling; Esters; Halides; Iodination; isomers; oxidation; Physical Sciences; Science & Technology; selenium; Stereoselectivity; isomers; oxidation; CONVENIENT; MECHANISMS; alkenes; CYCLO-ELIMINATION; ORGANOBORANES; CROSS-COUPLING REACTIONS; selenium; STEREOSELECTIVE-SYNTHESIS; HYDROBORATION-IODINATION; TRISUBSTITUTED OLEFINS; STEREOSPECIFIC CONVERSION; boron
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201610387

A stereodivergent coupling reaction between vinyl halides and boronic esters is described. This coupling process proceeds without a transition‐metal catalyst, instead proceeding by electrophilic selenation or iodination of a vinyl boronate complex followed by stereospecific syn or anti elimination. Chiral, nonracemic boronic esters could be coupled with complete enantiospecificity. The process enables the highly stereoselective synthesis of either the E or Z alkene from a single isomer of a vinyl coupling partner. Which way to go? A stereodivergent coupling process enables a highly stereoselective synthesis of alkenes, thus providing access to either isomer of the coupled product from a single isomer of a vinyl metal precursor. This coupling process proceeds without a transition‐metal catalyst, instead taking place by electrophilic iodination or selenation of a vinyl boronate complex followed by stereospecific anti or syn elimination.