| Hydrazines are a kind of valuable organic compounds.Many hydrazines show remarkable biological activities: For example,some drugs of hydrazines have a significant effect on the treatment of tuberculosis,hypertension,and Parkinson’s disease;Several drugs of hydrazines can effectively resist diseases such as SARS,AIDS,and hepatitis.Since the 21 th century,the methods for the synthesis of hydrazines have increased dramatically.It is worth mentioning that the exploration of synthetic methods for acyl hydrazides has become one of hot research topic.Generally,polysubstituted hydrazine derivatives can be synthesized by transition-metal-catalysis,reactions of organometallic reagents,photocatalysis,small-molecule organocatalysis and protective groups and deprotection methods.In the hydrazine family,N-Boc-protected N,N′-disbstituted hydrazines are very important.Typically,they can be synthesized via transition-metal-catalyzed(e.g.,Pd and Cu)or base-promoted(e.g.,n-Bu Li)amination reactions of hydrazines with haides or boronic acids.In this paper,we described a new method on the synthesis of N-Boc-protected N,N’-disubstituted hydrazines via radical generation and addition in situ of azocarboxylic tert-Butyl esters by using azo compounds as starting materials.The advantages of this method include broad substrate scope,benign conditions,and convenient operation. |
