Study of Aryl Triazoles for Absolute Configuration Determination
Date
2016Abstract
A variety of chiral mono- and di-1,4-disubstituted 1,2,3-triazoles were synthesized by CuAAC 'click chemistry' as model compounds and their spectroscopic properties characterized. The UV and CD study of these compounds showed that 4-substituted aryl triazoles give rise to moderate exciton CD curves, under either homo- or hetero-coupling. The direction of the electric transition moment of the non-symmetric chromophores was determined by conformational analysis and supported by NMR data. The signs of the Cotton effects of the CD spectra were in complete agreement with the determined directions of the electric transition moments of the chromophores. Therefore, 4-substituted aryl triazoles can be used for the determination of the absolute configuration of organic compounds. In addition, the 4–(4-bromo-phenyl)-1,2,3-triazole allows red-shifted chromophores to be obtained via Suzuki reactions, thus avoiding overlap with the substrate absorptions