Alternating Radical Stabilities: A Convergent Route to Terminal and Internal Boronates. Issue 47 (17th July 2019)

• Record Type: Journal Article
• Authors: Huang, Qi; Michalland, Jean; Zard, Samir Z.
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 47(2019)
• Page Start: 16936
• Page End: 16942
• Publication Date: 2019-07-17
• Subjects: aminoboronic acids -- boronates -- radical addition -- radical stabilities -- xanthates; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201906497
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Pinacolato boronates (Bpin) with an empty p‐orbital on boron stabilize an adjacent carbon radical, in contrast to diethanolamino boronates [B(DEA)] where the boron is sp 3 ‐hybridized. By alternately placing a pinacol or diethanolamine moiety on the boron atom, thus stabilizing or not stabilizing the corresponding adjacent radical, it is possible to control the behavior of α‐boronyl xanthates and construct a large variety of terminal or internal boronates in a modular fashion. The remarkable tolerance of polar groups and the ability to introduce quaternary centers are particularly noteworthy features of this process. Abstract : To stabilize or not to stabilize : Alternating the relative stabilities of intermediate radicals by switching the hybridization of the adjacent boron atom from sp 2 to sp 3 and vice versa provides a convenient method to control successive intermolecular radical additions, leading to complex, highly functionalized boronates.