219860-94-3Relevant articles and documents
Thermolysis of acylazo O-trimethylsilyl cyanohydrins: Azoalkanes yielding captodatively substituted radicals
Billera, Charles F.,Dunn, Travis B.,Barry, David A.,Engel, Paul S.
, p. 9763 - 9768 (1998)
A new synthetic method has been developed for preparing azoalkanes bearing geminal α-cyano and α-trimethylsiloxy groups. While the symmetrical compound 5 decomposes near room temperature to afford, almost entirely, the C-C dimers, the unsymmetrical azoalkane 3 requires heating to 75 °C. The thermolysis activation parameters of 3 and 5 can be rationalized on steric grounds without invoking captodative radical stabilization. A 13C NMR product study of photolyzed 3 in the presence of TEMPO at 21 °C shows that the fate of caged [tert-butyl, 1-trimethylsiloxy-1-cyanoethyl (14)] radical pairs is disproportionation, 17%, cage recombination, 20%, and cage escape, 63%.
