Reactions of Tetra(<i>o‐</i>tolyl)diborane(4) with Organic Azides: Formation of Fluorescent Boron‐Fused Hexazenes
Masahiro Yamamoto, Wing Chun Chan, Zhenyang Lin, Makoto Yamashita
Abstract
Abstract The reaction of tetra( o ‐tolyl)diborane(4) with organic azides afforded three different compounds, diborylamines, diboryltriazenes, and B 2 ‐hexazenes having a bicyclic B 2 N 6 ring system. The reaction with aryl azides gave diborylamines, while the reaction with 1 equiv. of alkyl azides furnished diboryltriazenes. In the case of the reaction with an excess amount of primary alkyl azide, a new heterocyclic B 2 ‐hexazenes were obtained. The formation of the B 2 N 6 structure could be explained by one general reaction mechanism via the diboryltriazene intermediate according to the control experiments and DFT calculations. The B 2 ‐hexazenes exhibited a strong fluorescence with a remarkably high fluorescent quantum yield of up to 96 %.