673-40-5Relevant articles and documents
Alternative method for the synthesis of triazenes from aryl diazonium salts
Abrams
supporting information, (2021/05/10)
An alternative mild method for access to 1-aryl-3,3-dimethyl alkyl triazenes is described. This protocol employs the dropwise addition of a methanolic solution of a carboxylate (RCO2M) or carbonate (CO32?) to a gently heated DMF solution containing an aryl diazonium salt (ArN2+), that had been previously isolated. Presumably homolysis of the weak N–O bond of diazo ether adducts formed in this operation initiates radical pathways that lead to the generation of triazene product. DMF serves as not only a one-electron donor to the diazonium salts employed in this process, but also as a source of dimethylamine radicals that act as a nucleophilic coupling partner. The reaction provides modest yields (ca. 20–40%) across an array of aryl diazonium salts that contain various substitution. Furthermore this unique approach to triazenes contrasts with traditional methods that employ dimethyl amine in reagent form which directly couples with diazonium salts. Seemingly, only one other example employing somewhat similar reaction conditions to this current investigation en route to triazenes has been reported, albeit with lower yields and for one representative example furnished as a side-product. The current work here improves upon the efficiency of this reported result, and further expands the reaction scope.
Azoacetylenes for the Synthesis of Arylazotriazole Photoswitches
Anderl, Felix,Balkenhohl, Moritz,Carreira, Erick M.,Fink, Moritz,Pfaff, Patrick
supporting information, p. 14495 - 14501 (2021/09/18)
We report a modular approach toward novel arylazotriazole photoswitches and their photophysical characterization. Addition of lithiated TIPS-acetylene to aryldiazonium tetrafluoroborate salts gives a wide range of azoacetylenes, constituting an underexplored class of stable intermediates.In situdesilylation transiently leads to terminal arylazoacetylenes that undergo copper-catalyzed cycloadditions (CuAAC) with a diverse collection of organoazides. These include complex molecules derived from natural products or drugs, such as colchicine, taxol, tamiflu, and arachidonic acid. The arylazotriazoles display near-quantitative photoisomerization and long thermalZ-half-lives. Using the method, we introduce for the first time the design and synthesis of a diacetylene platform. It permits implementation of consecutive and diversity-oriented approaches linking two different conjugants to independently addressable acetylenes within a common photoswitchable azotriazole. This is showcased in the synthesis of several photoswitchable conjugates, with potential applications as photoPROTACs and biotin conjugates.
Copper-mediated tandem ring-opening/cyclization reactions of cyclopropanols with aryldiazonium salts: Synthesis of: N -arylpyrazoles
Liu, Jidan,Xu, Erjie,Jiang, Jinyuan,Huang, Zeng,Zheng, Liyao,Liu, Zhao-Qing
supporting information, p. 2202 - 2205 (2020/02/26)
A general method for the synthesis of structurally diverse N-arylpyrazoles from readily available cyclopropanols and aryldiazonium salts is disclosed. The reaction was conducted at room temperature within minutes with a broad substrate scope and excellent regioselectivity.