First determination of the rate constant for ring-closure of an azahexenoyl radical: 6-aza-7-ethyl-5-hexenoyl

Competitive kinetic experiments utilising free radical carbonylation chemistry provide a first estimate for the rate constant for 6-endo cyclization of the 6-aza-7-ethyl-5-hexenoyl radical of (4.8 +/- 2.4) x 10(6) s(-1) at 90 degrees C in benzene, in good agreement with ONIOM-G3(MP2)-CC + COSMO-RS calculations (6.8 x 10(6) s(-1)).