Catalytic Direct Construction of Cyano-tetrazoles

Abstract

Cyano-tetrazole is the first reported compound that bears four nitrogen atoms in a single five-membered ring. This unique molecular scaffold has long been ignored after its discovery in 1885, mainly attributed to the scarcity of available synthetic methods. Indeed, the most popular approach to tetrazoles (that is the cycloaddition reaction between nitriles and azides) has inevitably excluded the possibility of introducing valuable cyano groups to decorate the final heterocyclic cores. Here, we describe a completely different disconnection strategy to the long time-pursued cyano-tetrazoles via a simple, direct, and practical cycloaddition transformation between readily accessible aryl diazonium salts and diazoacetonitrile. This method provides both regioisomers of disubstituted tetrazoles from the same set of starting materials in a metal cation controlled fashion.

Iron(II) Phthalocyanine-Catalyzed Olefination of Aldehydes with Diazoacetonitrile: A Novel Approach to Construct Alkenyl Nitriles

“…The diazoacetonitrile was prepared according to the reported method. 18 All 1 H, 13 C, and 31 P NMR spectra were recorded on a Bruker Avance III 400 MHz NMR spectrometer with tetramethylsilane (TMS) as internal reference in δ scale downfield from TMS. Coupling constants (J) were reported in hertz (Hz).…”

Recent Advances in Catalytic Nitrogen–Nitrogen Bond Formation Reactions

“…After an extensive follow-up study of diazo compounds as cycloaddition partners in the synthesis of substituted tetrazoles, , Marek, Zhang, Ma, and co-workers started the exploitation of highly reactive α-amino acid diazoketones which are normally considered as excellent precursors for silver-catalyzed Wolff rearrangement. In this work, a faster intermolecular [3 + 2] cycloaddition occurred by the utilization of aryldiazonium tetrafluoroborate 62 as the reaction partner to deliver amino acid-derived N -heterocycles 63 .…”

E3 ligase ligand chemistries: from building blocks to protein degraders

“…88 Recently, Xiao and colleagues described the silvercatalysed synthesis of cyano-tetrazoles via the intermediate aryl diazonium salts derived from pomalidomide and lenalidomide (Examples 19 and 20). 89 We propose that the aforementioned diazonium salts are valuable coupling partners for other types of organic syntheses. 90 Pomalidomide or lenalidomide were also the starting point for a photo-and ruthenium-catalysed late-stage sulfuration reaction that was employed for the synthesis of a library of thio ether (Examples 21 and 22) or seleno ether IMiD analogues with anti-myeloma activity.…”

“…88 Recently, Xiao and colleagues described the silver-catalysed synthesis of cyano-tetrazoles via the intermediate aryl diazonium salts derived from pomalidomide and lenalidomide (Examples 19 and 20). 89 We propose that the aforementioned diazonium salts are valuable coupling partners for other types of organic syntheses. 90…”