Entry to 4,5-fused coumarin frameworks radical-promoted alkylative intramolecular C5-annulation.

An unprecedented radical-promoted strategy involving a domino alkylation/intramolecular C5-annulation of -acryloyl-4-amino coumarin has been devised for the assembly of 4,5-fused coumarin scaffolds. This protocol employs silver-catalyzed oxidative decarboxylation for the generation of alkyl radicals from carboxylic acids, which were used as radical precursors. This method has also been extended to a diverse range of carbon-centered radicals generated from 2-oxo acids, a 1,3-dicarbonyl compound, isopropanol and acetone.

Regioselective cope rearrangement and prenyl transfers on indole scaffold mimicking fungal and bacterial dimethylallyltryptophan synthases.

Aromatic prenyltransferases are an actively mined enzymatic class whose biosynthetic repertoire is growing. Indole prenyltransferases catalyze the formation of a diverse set of prenylated tryptophan and diketopiperazines, leading to the formation of fungal toxins with prolific biological activities. At a fundamental level, the mechanism of C4-prenylation of l-tryptophan recently has surfaced to engage a debate between a "direct" electrophilic alkylation mechanism (for wt DMATS and FgaPT2) versus an indole C3-C4 "Cope" rearrangement followed by rearomatization (for mutant FgaPT2).