1-Substituted 1,2,3-triazoles represents‘privileged’structural scaffolds of many clinical pharmaceuticals.However,the traditional methods for their preparation mainly rely on thermal[3+2]cycloaddition of potentially...1-Substituted 1,2,3-triazoles represents‘privileged’structural scaffolds of many clinical pharmaceuticals.However,the traditional methods for their preparation mainly rely on thermal[3+2]cycloaddition of potentially dangerous acetylene and azides.Here we report a base-mediated[4+1]annulation of azoalkenes generated in situ from readily available difluoroacetaldehyde N-tosylhydrazones(DFHZ-Ts)with amines under relatively mild conditions.This azide-and acetylene-free strategy provides facile access to diverse 1-substituted 1,2,3-triazole derivatives in high yield in a regiospecific manner.This transformation has great functional group tolerance and can suit a broad substrate scope.Furthermore,the application of this novel methodology in the gram-scale synthesis of an antibiotic drug PH-027 and in the late-stage derivatization of several bioactive small molecules and clinical drugs demonstrated its generality,practicability and applicability.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,Nos.21871043,21961130376)Department of Science and Technology of Jilin Province(Nos.20180101185JC,20190701012GH,20200801065GH)the Fundamental Research Funds for the Central Universities(Nos.2412019ZD001,2412020ZD003)。
文摘1-Substituted 1,2,3-triazoles represents‘privileged’structural scaffolds of many clinical pharmaceuticals.However,the traditional methods for their preparation mainly rely on thermal[3+2]cycloaddition of potentially dangerous acetylene and azides.Here we report a base-mediated[4+1]annulation of azoalkenes generated in situ from readily available difluoroacetaldehyde N-tosylhydrazones(DFHZ-Ts)with amines under relatively mild conditions.This azide-and acetylene-free strategy provides facile access to diverse 1-substituted 1,2,3-triazole derivatives in high yield in a regiospecific manner.This transformation has great functional group tolerance and can suit a broad substrate scope.Furthermore,the application of this novel methodology in the gram-scale synthesis of an antibiotic drug PH-027 and in the late-stage derivatization of several bioactive small molecules and clinical drugs demonstrated its generality,practicability and applicability.
