| Trans-Diazenes have been known since the late nineteenth century as azo dyes. The cis aromatic and aliphatic diazenes have been known since 1937 and 1964 respectively. Diazenes are sources of free radicals in industrial polymerizations and have the advantage over peroxides because they decompose at lower temperature and peroxides sometimes undergo self induced decompositions. The more stable trans diazene when irradiated with UV light isomerizes to the less stable cis isomer. Thermally the cis diazene converts to trans or decomposes to radicals with the elimination of nitrogen. Bridgehead diazenes are the latest emergence in diazene chemistry. The smallest bridgehead diazene, bis-bicyclo[1.1.1]pentyldiazene could not be synthesized despite several previous attempts. We have successfully synthesized this compound from [1.1.1]propellane. [1.1.1]Propellane undergoes 1,3 free radical additions with or without a catalyst. A pseudo halogen, iodine azide, produces a nearly quantitative yield of 3-iodo-bicyclo[1.1.1]pentylazide 1. Reduction of 1 by several methods failed to provide 1-bicyclo[1.1.1]pentylamine. However, reduction of 1 with LAH followed by addition of HCl gas provided 3-methylene-cyclobutylaniine hydrochloride 2 and a 2-chloro-2-methylbutylamine hydrochloride 3 respectively. The mechanism of formation of 2 and 3 has been established. The hypochlorite oxidation of N,N′bis-(bicyclo[1.1.1]pentyl)sulfamide 4 provided azoxy-bicyclo[1.1.1]pentane. Trans-bis-bicyclo[1.1.1]pentyldiazene was obtained by reduction of azoxy-bicyclo[1.1.1]pentane with LAH. Several attempts to cis-bis-bicyclo[1.1.1]pentyldiazene from a photochemical reaction of trans-bis-bicyclo[1.1.1]pentyldiazene and chemical syntheses from 4 were unsuccessful. Based on the steady progress of cis absorption of bridgehead diazenes, the absorption of cis-bis-bicyclo[1.1.1]pentyldiazene has been estimated.; Cyclic azodioxide can be prepared from dinitro compounds in several steps. 2,3-Diazabicyclo[2.2.2]oct-2-ene (DBO) dioxide forms non-covalent complexes with tetracyanoethylene (TCNE). In order to study the catalytic activity, an attempt to make metal complexes with 3,3,4,4-tetramethyldiazene-N,N ′-dioxide did not work as expected.; 1-Cyanobenzotriazole acts as a source of -CN electrophile for introduction to a carbon center. Compounds like arylacetonitrile have been successfully used for introduction of a CN group as reported in a recent publication. Attempts to synthesize sec-phenethyl isocyanate, urea or an amine from the sec-phenethyl alcohol using 1-cyanobenzotriazole as an electrophile were unsuccessful indicating that the negatively charged oxygen, unlike carbon, behaves differently. |
