Photoredox-Catalyzed Decarboxylative C–H Acylation of Heteroarenes

A mild, environmentally friendly, and regioselective acylation of heterocycles with inexpensive carboxylic acids is reported via photoredox catalysis. The strategy is highlighted with good functional group tolerance and substrate scope which could rapidly realize the acylation of various heterocyclic compounds.

Quercetin-3-oleate

Polyphenols are well-known health promoting agents, but they have some limitations due to their spontaneous oxidation. This evidence has limited their use as drugs in recent years. In this field, several chemical modifications have been proposed to overcome these restrictions; among these, esterification seems to be the preferred modification. Ester derivatives may be able to reduce the bioavailability problems connected to polyphenols. On the other hand, the presence of esterase enzymes in the body guarantees ester hydrolysis, which in turn frees the two molecules that make it up. Lipase-catalyzed esterifications gave birth to several derivatives of flavonoids glycosides, in green conditions. In this short paper, pancreatic porcine lipase was firstly used as a cheap bio-catalyst, to synthesize oleoyl derivatives of quercetin in aglycone form. The results demonstrated how the enzyme is able to promote a regioselective acylation on C-3 position, with high yields and easy purification processes.