Aziridination of alkenes using 2-substituted-3-acetoxyamino-quinazolin-4(3H)-ones: changes in transition state geometry resulting from addition of trifluoroacetic acid or by an electron-withdrawing 2-substituent

Abstract

The effects of TFA on the competitive reactions of 3-acetoxyaminoquinazolinones 2 and 10 with methyl acrylate and with tert-butyl acrylate are interpreted as supporting a change in transition state geometry from one where (Q)CO/(ester)CO overlap 7b is replaced by (Q)CN⁺H/(ester)CO overlap 7c (Q = quinazolinone). Aziridinations of methyl or tert-butyl acrylate using 2-trifluoromethyl-substituted 3-acetoxyaminoquinazolinones 20 and 21 take place with (Q)CN/(ester)CO overlap 22 even in the absence of TFA.