• 대한화학회지
• /
• 제46권6호
• /
• pp.590-594
• /
• 2002

• Bulletin of the Korean Chemical Society
• /
• 제31권9호
• /
• pp.2453-2458
• /
• 2010

Photochemical studies of N-[(trimethylsilyl)alkyl]saccharins were carried out to investigate their photochemical behavior. Depending on the nature of the substrate and the solvent system employed, reactions of these substances can take place by either SET-promoted silyl migration from carbon to either the amide carbonyl or sulfonyl oxygen or by a N-S homolysis route. The results of the current studies show that an azomethine ylide, arising from a SET-promoted silyl migration pathway, is generated in photoreactions of N-[(trimethylsilyl)methyl]saccharin and this intermediate reacts to give various photoproducts depending on the conditions employed. In addition, irradiation of N-[(trimethylsily)ethyl]saccharin produces an excited state that reacts through two pathways, the relative importance is governed by solvent polarity and protic nature. Finally, photoirradiation of N-[(trimethylsilyl)propyl]saccharin in a highly polar solvent system comprised of 35% aqueous MeOH gives rise to formation of a tricyclic pyrrolizidine and saccharin that generated via competitive SET-promoted silyl transfer and $\gamma$-hydrogen abstraction pathways.

• Journal of Photoscience
• /
• 제12권2호
• /
• pp.63-66
• /
• 2005

The azomethine ylide forming photoreaction has been explored by probing the excited state chemistry of several N-trimethylsilylmethyl substituted cyclic and acyclic imides and amide analogs. N-[(Trimethylsilyl)methyl]-N-mesylbenzamide (5) undergoes the excited state C to O silyl migration reaction to produce azomethine ylide intermediate 13. This ylide undergoes electrocyclization to form transient aziridine intermediate 14 which react further by ring opening to generate N-phenacylamine product 10. On the other hand, photolysis of N-[N-mesyl-N-(trimethylsilyl)methyl]aminoethyl-N-mesylbenzamide (8) brings about desilylation resulting in the production of dimer 17.