New Boryl Radicals Derived from N-Heteroaryl Boranes: Generation and Reactivity

✍ Scribed by Prof. Jacques Lalevée; Dr. Nicolas Blanchard; Mohamad-Ali Tehfe; Anne-Caroline Chany; Prof. Jean-Pierre Fouassier

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 460 KB
• Volume: 16
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.201001440

✦ Synopsis

Abstract

Recently, boryl radicals have been the subject of revived interest. These structures were generated by hydrogen‐abstraction reactions from the corresponding boranes (i.e., from amine or phosphine boranes). However, the classical issue remains their high BH bond‐dissociation energy (BDE), thereby preventing a very efficient hydrogen‐abstraction process. In the present paper, new N‐heteroaryl boranes that exhibiting low BH BDE are presented; excellent hydrogen‐transfer properties have been found. Both the generation and the reactivity of the associated boryl radicals have been investigated through their direct observation in laser flash photolysis. The boryl radical interactions with double bonds, oxygen, oxidizing agent, and alkyl halides have been studied. Some selected applications of N‐heteroaryl boryl radicals as new polymerization‐initiating structures are proposed to evidence their high intrinsic reactivity.