Copper(II)-Catalyzed Aerobic Oxidative Synthesis of Substituted 1,2,3- and 1,2,4-Triazoles from Bisarylhydrazones via C–H Functionalization/C–C/N–N/C–N Bonds Formation

An unprecedented copper­(II)-catalyzed aerobic oxidative
synthesis
of 2,4,5-triaryl-1,2,3-triazoles and 1,3,5-triaryl-1,2,4-triazoles
from bisarylhydrazones as the common starting precursor has been achieved
via cascade C–H functionalization/C–C/N–N/C–N
bonds formation under mild reaction conditions. One of the enthralling
outcomes of this strategy is the copper­(II)-catalyzed room temperature
C–H functionalization/C–N bond formation in presence
of air, which has been accomplished during the synthesis of substituted
1,2,4-triazoles. This new class of compounds could give prospective
luminescence as an iconic component in the area of pharmaceutical
and biological sciences. The intermediates for both the processes
have been isolated to elucidate the mechanistic scenario.

本研究成功实现了前所未有的铜(II)催化需氧氧化合成策略：以双芳基腙(bisarylhydrazones)为通用起始原料，在温和反应条件下通过串联C-H官能化、C-C键、N-N键与C-N键形成的级联反应，合成2,4,5-三芳基-1,2,3-三唑与1,3,5-三芳基-1,2,4-三唑类化合物。该策略的一项引人瞩目的成果是，在取代1,2,4-三唑的合成过程中，实现了以空气为氧化剂的铜(II)催化室温C-H官能化/C-N键形成反应。这类新型化合物有望作为关键功能组分应用于医药与生物科学领域，展现出潜在的发光性能。本研究已分离得到两个反应路径的中间体，以阐明其反应机理。