A photocatalytic C−H disulfuration of indolizines was developed, giving an approach to a wide variety of indolizine-3-disulfides with good yields. Trisulfide dioxides were explored as a high-efficient disulfuration reagent. This disulfuration reaction could be scaled up to grams. Mechanistic studies support a photoinduced pathway involving the generation of indolizine cationic radicals. A bulky alkyl substituent on terminal sulfur of trisulfide dioxide A was necessary for selective formation of disulfide over monosulfide.
A practical and environmentally benign cascade multicomponent
condensation
of naphthol/thionaphthol/naphthylamine, formaldehyde, and DBU in water
without any catalysts has been achieved. A wide variety of dihydrooxazine,
dihydrothiazine, and tetrahydrobenzoquinazoline derivatives N-substituted
with a tether bearing a caprolactam unit were afforded in moderate
to good yields. The advantages of being cost-effective, metal-free,
and easily handled and the use of water as medium made this protocol
conform with the principle of green synthesis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.