118299-59-5Relevant academic research and scientific papers
Amine-Flavin Electron Transfer Photochemistry. Potential Models for Monoamine Oxidase Catalysis and Inhibition
Kim, Jong-Man,Cho, In-Seop,Mariano, Patrick S.
, p. 4943 - 4955 (2007/10/02)
The photoreactions of 3-methyllumiflavin (3MLF) and a variety of amines have been explored.These studies have demonstrated that 3MLF undergoes efficient photoreactions with α-silyl tertiary benzylamines to generate 4a-adducts by pathways involving sequential SET and desilylation followed by radical coupling.These adducts are unstable substances that react rapidly with nucleophiles (e.g., MeOH, H2O, and NaBH4) and oxygen.Theyare also photolabile, providing the corresponding 4a-benzyldihydroflavin upon irradiation.Non-silicon-containing primary and secondary amines also participate in SET-promoted photoreactions with 3MLF.The amine cation radicals formed in these processes undergo further transformations to produce radical intermediates by either α-CH or NH deprotonation pathways.The potential relevance of these findings to the area of monoamine oxidase chemistry is considered.
Radical cyclization reactions of α-silyl amine α,β-unsaturated ketone and ester systems promoted by single electron transfer photosensitization
Jeon, Yoon T.,Lee, Chao-Pin,Mariano, Patrick S.
, p. 8847 - 8863 (2007/10/02)
The results of a broad investigation of the preparative and mechanistic aspects of single electron transfer (SET) promoted photocyclization reactions of α-silyl amino and amido α,β-unsaturated esters and ketones are presented. A number of unique and synthetically useful features of these processes, driven by α-silyl amine and amide cation radical desilylation and by intramolecular conjugate addition of intermediate α-amino and α-amido carbon-centered radicals to unsaturated esters and ketones, are described. Comparisons of the SET-sensitized and direct irradiation promoted reactions of these systems have shown how the former method is superior in inducing photocyclization reactions in cases where the α,β-unsaturated ketone or ester excited states are too reactive to be quenched by SET from the tethered amine donors and where diradicals produced as intermediates in the direct-irradiation reactions undergo fragmentation rather than cyclization. The current efforts have also demonstrated that problems associated with the ready oxidation of intermediate α-amino radicals can be avoided by the proper selection of photosensitizer or amine N substituents. Lastly, the synthetic versatility of this chemistry, exemplified by its application to the preparation of a number of N-heterocyclic substances by pathways involving either exo or endo radical cyclization, is presented.
