Photochemical Transformations, 75. The Azo/Nitrene Route to <i>cis,cis</i>‐Trialkyltriaziridines, 2^1b) Photolysis of <i>syn</i>‐Azo Azides of Defined Proximity – Attempts for N₃ → N₃X Ring Enlargement

Abstract

Abstract The as yet unknown route to triaziridines by the addition of nitrenes to the π side of the NN bond is achieved intramolecularly by the photolysis (thermolysis) of syn ‐azo azide substrates with high proximity; the yields reflect the sterical (and possibly inductive) influences of the skeleton. The product composition is rather independent of the exciting light; intramolecular azo → azide energy transfer is assumed. The kinetic skeleton stabilization of the triaziridines permits the synthesis of 17 ( 18 ) by the thermolysis of 7 ( 8 ) at 200°C with the product composition deviating only marginally from that of the photolysis. Attempts towards enlargement of the triaziridines to N 3 X rings (XCHR, O, NR) lead exclusively to products of intramolecular fragmentation.