A series of photochromic four-coordinate spirocyclic boron(iii) compounds that display thermally activated upconversion processes from the lower-lying unreactive excited state to the higher-lying photoreactive excited state is reported.
Pyridine−borane complexes were synthesized from 2-arylpyridines through an electrophilic aromatic borylation reaction with BBr3. The intermediate 2-(2-dibromoborylaryl)pyridines were stable enough to be handled in air and served as the synthetic platform for variously substituted pyridine−borane complexes. This facile method would be useful for the synthesis of aza-π-conjugated materials having boron−nitrogen
Boron‐Mediated Regioselective Aromatic C−H Functionalization via an Aryl BF
<sub>2</sub>
Complex
作者:Ganesh H. Shinde、Henrik Sundén
DOI:10.1002/chem.202203505
日期:2023.2.16
Regioselectivefunctionalization of 2-aryl-azaarenes N-heteroarenes and aryl aldehydes has been achieved. The reaction proceeds via a BBr3 promoted 5 and 6-membered boracycle that undergoes a ligand exchange promoted by Selectfluor to give a previously scarce aryl BF2 species. The aryl BF2 is a bench stable intermediate that can be used for the deborylative functionalization of the 2-aryl-azaarenes