Selective N-Nitrosation of Amines,<i>N</i>-Alkylamides and<i>N</i>-Alkylureasby N<sub>2</sub>O<sub>4</sub>Supported on Cross-Linked Polyvinylpyrrolidone(PVP-N<sub>2</sub>O<sub>4</sub>)
N2O4 was supported on the cross-linked polyvinylpyrrolidone (PVP) to afford a solid, stable and recyclable nitrosating agent. This reagent shows excellent selectivity for N-nitrosation of dialkyl amines in the presence of diaryl-, arylalkyl-, trialkylamines and also for secondary amides in dichloromethane at room temperature under mild and heterogeneous conditions. Also N-nitroso-N-alkyl amides can be selectively prepared in the presence of primary amides and N-phenylamides under similar reaction conditions. Selective N-nitrosation or dealkylation and N-nitrosation of tertiary amines can also be performed by this reagent.
Abstract Efficient N‐nitrosation of amines, amides, and ureas, and also S‐nitrosation of thiols were performed with dinitrogentetroxide impregnated on activated charcoal (N2O4/charcoal) in CH2Cl2 at room temperature. High selectivity was observed for N‐nitrosation of dialkyl amines, N‐alkylamides and N‐alkylureas. Dealkylation and N‐nitrosation of trialkylamines were also performed by this reagent
Photoreaction of nitroso-compounds in solution. Part XIV. Reactions of amido-radicals
作者:Y. L. Chow、J. N. S. Tam
DOI:10.1039/j39700001138
日期:——
extensive β-scission of C–H and C–C bonds, in benzene solution, shown by isolation of the appropriate fragmentation products. Although the reactions of amido-radicals were similar to those of alkoxy-radicals, β-scission of the C–Ar bond was not detected. Oxygen did not quench the primary photo-processes nor interfere with the reactions of the amido-radical.
17O-Labelled aminyloxides 4 and 7 have been prepared either by direct reaction of the intermediate aminyl radicals 3 and 6 generated by various methods, with 17O-enriched oxygen, or by spin trap reactions performed with 17O-labelled 2-methyl-2-nitrosopropane (8) and 2-methyl-2-nitropropane (13) respectively. Reaction of 17O-labelled tert-butylhydroxylamine with phosgen yielded 11 which was transformed