Grignard reagent dictated copper(I) phosphines catalyzed reductive coupling of diazo compounds: The chemistry beyond carbene generation

AbstractCopper‐dppf catalyzed reductive coupling of diazo compounds through terminal nitrogen is reported. However, copper catalysts are known to produce carbene from diazo compounds; the reaction conditions played an important role in the formation of diazine over carbene generation. Several control experiments have been conducted to understand the reaction mechanism and found that the formation of a copper–Mg heterobimetallic complex would be responsible for the observed reactivity pattern. The reaction produced diazine as a reductive coupling product along with biphenyl as a by‐product. All the synthesized diazines have been characterized fully by using analytical and spectroscopic techniques.