Geminale Vinyldiazide, X. 3,3‐Diazido‐2‐cyanacrylsäure‐methylester: Synthese von Vinylaziden, 4,5‐Dihydro‐1H‐tetrazol‐5‐ylidenen, Oxazolen und N‐Cyaniminen

Abstract

Reaction of methyl 3,3-diazido-2-cyanoacrylate (1) with amines 2 at -30°C yields aminovinyl azides 4. In the presence of equivalent amounts of triethylamine the vinyl azides 4 undergo 1,Y-ring closure to afford the triethylammonium salts 5. Treatment of 5 with hydrochloric acid gives the corresponding 4,5-dihydro-lH-tetrazo1-5-ylidene derivatives 6. In contrast thermolysis of 4 leads via azirines 7 to oxazoles 8. Reaction of vinyl diazide 1 with lysine and cystine, respectively, yields bis(viny1 azides) 9. Triethylamine-induced 1,5'-ring closure of 9 produces the bis(triethy1ammonium) salts 10, which can be transformed under acidic conditions into the corresponding bis(4,5-dihydro-lH-tetrazol-5-ylidene) derivatives 11. With methyl acrylate (

Synthesis and Chemistry of Organic Geminal Di- and Triazides

“…While the photochemical decomposition was not examined in further detail, the thermal reaction of geminal vinyl diazides is well-studied (Scheme 17) [95,96,97,98,103,104,105,106,107,108]. The key intermediate is the very electrophilic [109] double acceptor-substituted N -cyanoimine 86 .…”

“…The key intermediate is the very electrophilic [109] double acceptor-substituted N -cyanoimine 86 . At temperatures over 20 °C, geminal vinyl diazides loose one molecule of nitrogen forming an azidoazirine 84 , which spontaneously cyclizes to the tetrazole 85 [108]. After loss of a second molecule of nitrogen and subsequent rearrangement, the N -cyanoimine 86 is generated.…”

“…After loss of a second molecule of nitrogen and subsequent rearrangement, the N -cyanoimine 86 is generated. The N -cyanoimine 86 has been characterized in solution [97,108]; all isolation attempts led to polymerization [108,109]. The existence of this intermediate 86 was also proven by cycloaddition with 2,3-dimethylbuta-1,3-diene leading to the Diels-Alder product 87 [95,96,97,108,109].…”

“…The N -cyanoimine 86 has been characterized in solution [97,108]; all isolation attempts led to polymerization [108,109]. The existence of this intermediate 86 was also proven by cycloaddition with 2,3-dimethylbuta-1,3-diene leading to the Diels-Alder product 87 [95,96,97,108,109]. In the presence of alcohols [95,96,108,109] or amines [104,105,106,107,108], the N -cyanoimine 86 is immediately attacked at the electrophilic carbon and, after elimination of hydrogen cyanide, isolable structures 88 and 89 are obtained in good yields.…”

Synthesis and polymerizability of CN monomers

“…Gazit and Rappoport, 8 Saalfranck et al, 9 and Hoz and Speizman 10 reported a remarkable new method to make ¼ ¼NACN compounds with one or two acceptor substituents on C: reaction of an activated vinylic dihalide with two equivalents of sodium azide leads to the unstable gem-diazide, which after loss of two equivalents of nitrogen leads via an azacyclopropene to the substituted N-cyanoimine. Using Bis-trimethylsilylcarbodiimide The reaction of bis-trimethylsilylcarbodiimide with carbonyl compounds, catalyzed by titanium tetrachloride or trimethylsilyl triflate, is an alternate method to introduce the ¼ ¼NCN group; this reaction was first used by Aumueller and Huenig to make the bis(cyanoimine) derivative of benzoquinone.…”