Photoredox-Mediated Reaction of gem-Diborylalkenes: Reactivity Toward Diverse 1,1-Bisborylalkanes

Nivesh Kumar; Nadim Eghbarieh; Tamar Stein; Alexander I Shames; Ahmad Masarwa

doi:10.1002/chem.202000603

Photoredox-Mediated Reaction of gem-Diborylalkenes: Reactivity Toward Diverse 1,1-Bisborylalkanes

Chemistry. 2020 Apr 24;26(24):5360-5364. doi: 10.1002/chem.202000603. Epub 2020 Apr 15.

Authors

Nivesh Kumar¹, Nadim Eghbarieh¹, Tamar Stein², Alexander I Shames³, Ahmad Masarwa¹

Affiliations

¹ Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel.
² Fritz Haber Center for Molecular Dynamics Research, Institute of Chemistry, The Hebrew University Jerusalem, Jerusalem, 91904, Israel.
³ Physics Department, Ben-Gurion University of the Negev, 8410501, Be'er Sheva, Israel.

PMID: 32141638
DOI: 10.1002/chem.202000603

Abstract

The use of gem-diborylalkenes as radical-reactive groups is explored for the first time. These reactions provide an efficient and general method for the photochemical conversion of gem-diborylalkenes to rapidly access 1,1-bisborylalkanes. This method exploits a novel photoredox decarboxylative radical addition to gem-diborylalkenes to afford α-gem-diboryl carbon-centered radicals, which benefit from additional stability by virtue of an interaction with the empty p-orbitals on borons. The reaction offers a highly modular and regioselective approach to γ-amino gem-diborylalkanes. Furthermore, EPR spectroscopy and DFT calculations have provided insight into the radical mechanism underlying the photochemistry reaction and the stability of the bis-metalated radicals, respectively.

Keywords: decarboxylation; gem-bisboronates; organoborones; photochemistry; radicals.