Synthesis of benzotriazoles
A [3 + 2] cycloaddition of azides to benzynes affords a rapid and easy entry to a variety of substituted, functionalized benzotriazoles under mild conditions.
F. Shi, J. P. Waldo, Y. Chen, R. C. Larock, Org. Lett., 2008, 10, 2409-2412.
A 1,7-palladium migration-cyclization-dealkylation sequence for the regioselective synthesis of benzotriazoles proceed in excellent yields with high regioselectivities. The mechanism of the reaction has also been investigated.
J. Zhou, J. He, B. Wang, W. Yang, H. Ren, J. Am. Chem. Soc., 2011, 133, 6868-6870.
C-H activation of aryl triazene compounds followed by intramolecular amination in the presence of a catalytic amount of Pd(OAc)2 provides 1-aryl-1H-benzotriazoles at moderate temperature.
R. K. Kumar, M. A. Ali, T. Punniyamurthy, Org. Lett., 2011, 13, 2102-2105.
A cyclocondensation of 2-(arylamino)aryliminophosphoranes enables the synthesis of 1-aryl-1,2,3-benzotriazoles under mild conditions. The reaction involves a three-step, halogen-free route starting from simple nitroarenes and arylamines.
E. Łukasik, Z. Wróbel, Synlett, 2014, 25, 1987-1990.