496864-39-2Relevant academic research and scientific papers
Kinetic and theoretical study of 4-exo ring closures of carbamoyl radicals onto C=C and C=N bonds
DiLabio, Gino A.,Scanlan, Eoin M.,Walton, John C.
, p. 155 - 158 (2007/10/03)
(Chemical Equation Presented) Carbamoyl radicals were generated from oxime oxalate amides, and the kinetics of their 4-exo cyclizations onto C=C and C=NO bonds, leading to β-lactam-containing species, were studied by EPR spectroscopy. DFT computations wit
Preparation of β- and γ-lactams from carbamoyl radicals derived from oxime oxalate amides
Scanlan, Eoin M.,Slawin, Alexandra M.Z.,Walton, John C.
, p. 716 - 724 (2007/10/03)
A general synthetic route to oxime oxalate amides was developed and applied to the preparation of molecules incorporating N-benzyl-N-alkenyl amides linked with acetone oxime or benzaldoxime units. In addition, 2-substituted-thiazolidine-4-carboxylic acid methyl ester amides of oxalyl benzaldoxime were also prepared. It was shown by EPR spectroscopy that the oxalyl benzaldoxime amides dissociated to produce benziminyl and carbamoyl (aminoacyl) radicals when photolysed with 4-methoxyacetophenone as a photosensitizer. Carbamoyl radicals derived from N-alk-3-enyl oxime oxalate amides underwent ring closure to afford pyrrolidin-2-ones. The analogous N-alk-2-enyl precursors afforded azetidin-2-ones. Reactions of the cyclohexenyl and cinnamyl oxime oxalate amides afforded a bicyclic β-lactam and a 3-benzyl-substituted β-lactam respectively. Interestingly, both products were isolated as hydroxylated compounds. A thiazolidine-derived oxime oxalate amide containing an isobutenyl side chain also dissociated with production of the corresponding thiazolidinyl-carbamoyl radical, as shown by EPR spectroscopy. GC-MS evidence indicated that this radical cyclised to afford some of the corresponding penicillin derivative.
