Synfacts 2011(1): 0016-0016  
DOI: 10.1055/s-0030-1259207
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Palladium-Catalyzed Synthesis of 1,3,4-Benzotriazepines and Indazoles

Contributor(s): Victor Snieckus, Johnathan Board
C. Dong*, L. Xie, X. Mou, Y. Zhong, W. Su
Wuhan University, P. R. of China
Further Information

Publication History

Publication Date:
21 December 2010 (online)

Significance

Reported is the synthesis of either benzotriazepines or indazoles through the palladium-catalyzed reaction of ortho-halophenyl hydrazones with aromatic isocyanates. The reaction consists of a C-N bond forming step and isocya­nate condensation. The course of the reaction is very substrate-dependent, with both potential products often being formed. For benzotriazepine formation, the reaction gives better yields as the size of R increases. In the case of indazoles, yields improve when moving from R = Me to R = n-Pent, but then dramatically decrease when R = Ph. The nature of the aryl isocyanate also greatly affected the course of the reaction, with electron-donating groups increasing the yield dramatically in the case of the benzotriazepines, but less so in the case of the indazoles.