N-Acyl-N-alkylcarbamoyloxy radicals: Entries to amidyl radicals by decar☐ylation and to α-amide radicals by radical translocation
摘要:
N'-Acyl-N-hydroxypyridine-2-thione carbamates react in radical chain reactions to give the title radicals which can decarboxylate or react by intramolecular hydrogen atom transfer; the competing reaction pathways are controlled by the structure of the alkyl group and the conformation of the precursor which can be influenced by addition of a Lewis acid.
N-Acyl-N-alkylcarbamoyloxy radicals: Entries to amidyl radicals by decar☐ylation and to α-amide radicals by radical translocation
作者:John L. Esker、Martin Newcomb
DOI:10.1016/s0040-4039(00)61087-0
日期:1992.9
N'-Acyl-N-hydroxypyridine-2-thione carbamates react in radical chain reactions to give the title radicals which can decarboxylate or react by intramolecular hydrogen atom transfer; the competing reaction pathways are controlled by the structure of the alkyl group and the conformation of the precursor which can be influenced by addition of a Lewis acid.
Cleavage of spirooxaziridines by the action of ferrous sulfate
作者:E. Schmitz、N. I. Kapustina、H. Sonnestein、G. I. Nikishin
DOI:10.1007/bf00958590
日期:1991.4
The reaction of 2-butyl-3,3-(1'-heptyl)tetramethyleneoxaziridine with ferrous sulfate gave the N-butylamides of E- and Z-4-dodecenecarboxylic and E- and Z-5-dodecenecarboxylic acids in approximately 1:1 ratio. Analogously, 2-butyl-3,3-(1'-alkyl)pentamethyleneoxaziridines gave the N-butylamides of the corresponding E- and Z-unsaturated carboxylic acids.
SHMITTS, E.;KAPUSTINA, I. I.;ZONNESHAJN, X.;NIKISHIN, G. I., IZV. AN CCCP. CEP. XIM.,(1991) N, S. 954-958
作者:SHMITTS, E.、KAPUSTINA, I. I.、ZONNESHAJN, X.、NIKISHIN, G. I.
DOI:——
日期:——
Esker John L., Newcomb Martin, J. Org. Chem, 59 (1994) N 10, S 2779-2786
作者:Esker John L., Newcomb Martin
DOI:——
日期:——
Multiple Reaction Channels of (N-Acyl-N-alkylcarbamoyl)oxyl Radicals from N-Acyl PTOC Carbamates
作者:John L. Esker、Martin Newcomb
DOI:10.1021/jo00089a023
日期:1994.5
N-Acyl-N-alkyl-N'-hydroxypyridine-2-thione carbamates (N-acyl PTOC carbamates) 1 are prepared in good to excellent yield by reactions of N-acylcarbamoyl chlorides with N-hydroxypyridine-2-thione sodium salt. Methods for production of the requisite carbamoyl chlorides by reaction of a secondary amide with trimethylsilyl triflate followed by treatment with phosgene were optimized. Precursors 1 react in radical chain reactions to give the title radicals (2) that can further react by several pathways. Decarboxylations of radicals 2 give amidyl radicals, and this method is excellent for production of acetamidyl radicals and in particular the N-methylacetarnidyl radical which is difficult to prepare by other routes. 5-Exo cyclizations of amidyl radicals produced by decarboxylation of 2 give, ultimately, lactams and N-acylpyrrolidines. 1,5-Hydrogen transfer reactions of 2 to give alpha-amide radicals compete with decarboxylation; cyclization of an alpha-amide radical thus formed also is reported. The Lewis acid MgBr2 can reduce the 1,5-hydrogen atom transfer reaction apparently by a chelation effect on the precursor that leads to production of radical 2 in a conformation unfavorable for hydrogen atom transfer. By appropriate experimental design, radicals 2 often can be directed toward one desired reaction, and several relative rate constants for reactions of 2 necessary for such design were determined in this work.