Some New Reactions Of Trifluoromethylsulfonyl Hydrazides And Acylhydrazides

Sulfonyl hydrazides and acylhydrazides are important hydrazine derivatives,which are widely used in organic synthetic, structure identification and so on. Our research group studied on sulfonyl hydrazides and acylhydrazides in details.Fortunately we found that sulfonyl hydrazides can be used as an aryl agents or sulfur agents involved in the reactions, and the acylhydrazides can be used as an aryl or ester groups involved in the reactions. On this basis, we envisioned that TfNHNHBoc could act as a new type of trifluoromethyl agents to react with olefins, as a new trifluoromethylthio agents to react with indoles. At last, we find that acylhydrazides could occur the rearrangement reaction promoted by benzyne, thus expanding the applications of hydrazine derivatives in the organic synthesis.This dissertation includes four chapters.Chapter 1: Research progress in the reaction of sulfonyl hydrazides and acylhydrazidesThis chapter gives an overview of the reactions of sulfonyl hydrazides in the terms of arylating agents via C-S bong cleavage, and in the terms of sulfenylating agents via S-N bong cleavage. Then we review the reactions of acylhydrazides.Chapter 2: Vicinal Difunctionalization of Terminal Alkenes with TfNHNHBocIn the past, the trifluoromethyl agents are difficult to handle, or hard to synthesize, or low reaction activity and requiring a large amount of agents. We discover that TfNHNHBoc can be used as a novel trifluoromethylating agent for the first time. To 5 mol% of CuCl as catalyst, NaCl as the Cl sources, TBHP as the oxidant, DMSO/H2O as solvents, TfNHNHBoc smoothly undergo chlorotrifluoromethylation with arylalkenes. By simply replacing NaCl and catalyst CuCl with NaBr and catalyst CuBr, respectively, the same reaction conditions are successfully applied to the vicinal bromotrifluoromethylation of arylalkenes.We are happy to find that TfNHNHBoc served as a novel trifluoromethylating agent for the tandem trifluoromethylation/cyclization of N-arylacrylamides under metal-free conditions. The consumption of TfNHNHBoc is 1.2 equivalents, and the reaction just need K2S2O8 as the oxidant. Preliminary mechanistic studies suggest that reactions proceed via radical pathways.Chapter 3: Trifluoromethylthiolation of indole with TfNENHNHBocIn the past, the trifluoromethylthioylation of indoles require the use of CF3SCl which is gaseous and toxic, or complex N-SCF3 and O-SCF3 agents, or large amounts of reducing agents. We firstly report TfNHNHBoc react as novel trifluoromethylthiolation agents. To 10 mol% of CuCl as catalyst, DMSO as the oxidant, CH3CN as solvents, TfNHNHBoc smoothly undergo trifluoromethylthiolation with indoles with no need of extra reducing agents. 2,4,5,6 and 7 position in indoles can be connected with substituents.Trifluoromethylthiolation of pyrroles could also be carried out smoothly at this conditions.Chapter 4: Benzyne-Promoted Curtius-Type Rearrangement of Acyl HydrazidesWe envision the rearrangement of acylhydrazides in the presence of benzyne under mild conditions. The reactions are applicable to a wide range of primary alcohols, secondary alcohols, alkyl acylhydrazides, aryl acylhydrazides and heterocyclic acylhydrazides. The configurations of a-position in acylhydrazides are maintained during the reaction. N and S nucleophiles could participate in the reaction to get the corresponding ureas and carbamate thioesters.