Related Experiment Video
Updated: Aug 21, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Construction of Unsymmetrical B─B Bond via Carboranyl Radical
Shimeng Li1,2, Yizhen Liu1, Zuowei Xie1
1Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, China.
Abstract:
This work describes a general method for constructing unsymmetrical B(cage)-B single bond at room temperature via boron-centered carboranyl radicals. The approach enables the efficient utilization of both boron atoms from B2cat2 with very high yields. The key hypercoordinate boron radical intermediates are generated through a visible-light-driven Ni(I)/Ni(II) redox cycle employing zinc as the reducing agent. These radicals react directly with B2cat2 to form B─B bond, which can subsequently undergo further derivatizations including boronic ester formation and hydroxylation.
Related Concept Videos
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Radical Formation: Addition
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an unpaired...
Radical Reactivity: Intramolecular vs Intermolecular
Radical Formation: Overview
Radicals from spin-paired molecules:
Radicals can be obtained from spin-paired molecules either by homolysis or electron transfer. While two radicals are formed in the former, an electron is added in the latter, also known...
Nucleophilic Aromatic Substitution: Elimination–Addition
Radical Chain-Growth Polymerization: Overview

