ChemInform Abstract: Functionalization of Phenyl Rings by Imidoylnitrenes.

Abstract

The nitrenes (II), generated by thermolysis of the azides (I), react with the monosubstituted benzenes (III), producing the p‐ or o‐phenylated isoureas (IV) and (V).

Functionalization of Phenyl Rings by Imidoylnitrenes. 3 The Effects of Resonance, Steric, and Inductive Properties on the Reactivity or Selectivity of Nitrenes and the Stability of their Precursors

“…The Hammett plots for the log of ortho/para ratio gave no correlation with substituent constant σ-values indicating that ortho/para selectivity is a fast process and is not rate-controling step. This supported our earlier prediction that formation of σ-complex (instead of benzaziridine) is a fast thermodynamically favored process [ 1 ]. The decomposition point of imidoyl azides or reactivity of imidoylnitrenes is controlled by slight change in the electron availability of Y (YO-C=N-Z)-.…”

“…The sensitivity of the imidoylnitrenes to Z substituents [(Y-O-C=N-Z)-N:] is well documented [ 1 , 2 ]. In this work, the sensitivity of the imidoylnitrenes (electronic and steric hindrance) to Y substituents is investigated.…”

“…For details on the use of 1 H-NMR in this work see references [ 1 , 2 and 7 ]. The tetrazoles 5-phenoxytetrazole ( 1T ), 5-(4-methylphenoxy)tetrazole ( 2T ), 5-(4-methoxyphenoxy)tetrazole ( 4T ) and 5-(4-chlorophenoxy)tetrazole ( 5T ), were prepared by the method of Martin and Weise [ 4 ]; 5-(4-nitro-phenoxy)tetrazole ( 5T ) [ 5 ] and 2,6-dimethylphenoxytetrazole ( 3T ) were reported earlier [ 1 , 2 , 6 , 7 ].…”

“…For details on the use of 1 H-NMR in this work see references [ 1 , 2 and 7 ]. The tetrazoles 5-phenoxytetrazole ( 1T ), 5-(4-methylphenoxy)tetrazole ( 2T ), 5-(4-methoxyphenoxy)tetrazole ( 4T ) and 5-(4-chlorophenoxy)tetrazole ( 5T ), were prepared by the method of Martin and Weise [ 4 ]; 5-(4-nitro-phenoxy)tetrazole ( 5T ) [ 5 ] and 2,6-dimethylphenoxytetrazole ( 3T ) were reported earlier [ 1 , 2 , 6 , 7 ]. The preparation of the azides N'-(p-toluenesulfonylphenoxy)carbimidoyl azide ( 1 ), N'-(p-toluenesulfonyl-4-methylphenoxy)carbimidoyl azide ( 2 ), N'-(p-toluenesulfonyl-2,6-dimethylphenoxy)carbimidoyl azide ( 3 ), N'-(p-toluenesulfonyl-4-methoxyphenoxy)carbimidoyl azide ( 4 ), N'-(p-toluenesulfonyl)(4-chloro-phenoxy)carbimidoyl azide ( 5 ), N'-(p-toluenesulfonyl-4-bromophenoxy)carbimidoyl azide ( 6 ), N'-(p-toluenesulfonyl-4-nitrophenoxy)carbimidoyl azide ( 7 ), N'-(p-toluenesulfonyl-2,4,6-trimethylphenoxy)-carbimidoyl azide ( 8 ), N'-(mesitylsulfonyl-2,4,6-trimethylphenoxy)carbimidoyl azide ( 9 ) and N'-cyano-2,4,6-trimethylphenoxycarbimidoyl azide ( 10 ) were also reported earlier [ 7 ].…”

“…The sensitivity of nitrene reactivity to the electronic properties of Z in [YO-(C=N-Z)-N:] has been established [ 1 ]. The more electron-withdrawing the Z group is the greater the more reactivity the nitrene.…”