The use of a halogen bond donor to
catalyze Friedel–Crafts
reactions of indoles with a range of aldehydes and ketones to directly
produce bis(indolyl)methanes, including the natural products arsindoline
A, arundine, trisindoline, and vibrindole A, is reported. The bidentate
catalyst used in these reactions proved to be more effective than
a monondentate analogue, a thiourea commonly used as an organocatalyst,
and even a trityl cation that has been used previously in the synthesis
of bis(indolyl)methanes.
With CoL2 as cocatalyst and eosin Y as sensitizer, the noble-metal-free heterogeneous CoL2/TiO2 system shows much efficient and more stable hydrogen evolution activity than that of the homogeneous system under visible light irradiation.
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.