Reductive Insertion of Elemental Chalcogens into Boron–Boron Multiple Bonds1. Issue 35 (26th June 2015)

• Record Type: Journal Article
• Authors: Braunschweig, Holger; Dellermann, Theresa; Ewing, William C.; Kramer, Thomas; Schneider, Christoph; Ullrich, Stefan
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 35(2015)
• Page Start: 10271
• Page End: 10275
• Publication Date: 2015-06-26
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201503398
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The syntheses of sulfur‐ and selenium‐bridged cyclic compounds containing boron stabilized by N‐heterocyclic carbenes (NHCs) have been achieved by the reductive insertion of elemental chalcogens into boron–boron multiple bonds. The three pairs of bonding electrons between the boron atoms in the triply bonded diboryne enabled six‐electron reduction reactions, resulting in the formation of [2.2.1]‐bicyclic systems wherein bridgehead boron atoms are spanned by three chalcogen bridges. A similar reaction using a diborene (boron–boron double bond) resulted in the reductive transfer of both pairs of bonding electrons to three sulfur atoms, yielding a NHC‐stabilized trisulfidodiborolane. The demonstration of these six‐ and four‐electron reductions lends support to the presence of three and two pairs of bonding electrons between the boron atoms of the diboryne and diborene, respectively, a fact that may be useful in future discussions on bond order.</p> </abstract>