Visible-Light-Promoted
Photoaddition of N‑Nitrosopiperidines to Alkynes:
Continuous Flow Chemistry
Approach to Tetrahydroimidazo[1,2‑a]pyridine
1‑Oxides
posted on 2022-08-03, 19:38authored byDilip
V. Patil, Yulim Lee, Hun Young Kim, Kyungsoo Oh
The photoaddition of N-nitrosopiperidines
to terminal
alkynes was effected under visible-light irradiation, in which a novel
synthetic access to tetrahydroimidazo[1,2-a]pyridine
1-oxides was achieved via the dehydrogenative cycloisomerization of
β-nitroso enamine intermediates. The decomposition pathways
of N-nitrosamines, alkynes, and β-nitroso enamine
intermediates were better handled in a continuous flow setting through
the diffusion control of chemical species that negatively affected
the formation of tetrahydroimidazo[1,2-a]pyridine
1-oxides under batch reaction conditions.