Hydrazine Hydrate Accelerates Neocuproine-Copper Complex Generation and Utilization in Alkyne Reduction, a Significant Supplement Method for Catalytic Hydrogenation

Diimine (HN=NH) is a strong reducing agent, but the efficiency of diimine oxidized from hydrazine hydrate or its derivatives is still not good enough. Herein, we report an in situ neocuproine-copper complex formation method. The redox potential of this complex enable it can serve as an ideal redox catalyst in the synthesis of diimine by oxidation of hydrazine hydrate, and we successfully applied this technique in the reduction of alkynes. This reduction method displays a broadfunctional group tolerance and substrate adaptability as well as the advantages of safety and high efficiency. Especially, nitro, benzyl, boc, and sulfur containing alkynes can be reduced to the corresponding alkalies directly, which provides a useful complementary method to traditional catalytic hydrogenation. Besides, we applied this method in the preparation of the mechanism. Alzheimer's disease drug CT-1812 and studied the mechanism.

Automated summary

In this study, an in situ neocuproine-copper complex formation method was reported for the synthesis of diimine and reduction of alkynes. The method shows a broad functional group tolerance and substrate adaptability, as well as advantages of safety and high efficiency. Furthermore, it provides a useful complementary method to traditional catalytic hydrogenation for reducing nitro, benzyl, boc, and sulfur containing alkynes.