Thermal and Photolytic Transformation of NHC-B,N-Heterocycles: Controlled Generation of Blue Fluorescent 1,3-Azaborinine Derivatives and 1H-Imidazo[1,2-a]indoles by External Stimuli

• Published in: Chemistry : a European journal Vol. 21; no. 40; pp. 13961 - 13970
• Main Authors: McDonald, Sean M., Mellerup, Soren K., Peng, Jinbao, Yang, Dengtao, Li, Quan-Song, Wang, Suning
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 28-09-2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: 1,3‐azaborinine; 3-azaborinine; B,N‐heterocycles; Carbenes; Chemistry; Derivatives; Fluorescence; Formations; imidazoindoles; N-heterocycles; Pathways; photolysis; Precursors; Stimuli; thermal isomerization; Transformations; 1,3-azaborinine; B,N-heterocycles; imidazoindoles; thermal isomerization; photolysis
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201502385

NHC–B,N‐heterocyclic compounds have been found to act as convenient precursors for obtaining either 1,3‐azaborinine or 1H‐imidazo[1,2‐a]indole derivatives, which are two different and rare classes of compounds. The formation of these two classes of compounds from the NHC–B,N‐heterocycles is highly selective depending on the external stimuli employed, and the resulting products have been studied for their interesting chemical and photophysical properties. The mechanism and possible reaction pathways of the unusual transformation are established by computational studies.
Take your pick: B,N‐heterocycles supported by an N‐heterocyclic carbene (NHC) show distinct and highly selective responses toward light and heat, generating rare species such as imidazo[1,2‐a]indole and blue fluorescent 1,3‐azaborinine derivatives.