[GRAPHICS]A novel approach to coumarin derivatives has been developed starting from readily available 2-(1-hydroxyprop-2-ynyl)phenols, based on an unprecedented palladium-catalyzed dicarbonylation process. Reactions were carried out in the presence of catalytic amounts of PdI2 in conjunction with an excess of KI in MeOH as the solvent at room temperature and under 90 atm of CO to give 3-[(methoxycarbonyl)-methyl]coumarins in good to high isolated yields (62-87%).
Photochemical α-carboxyalkylation of tryptophols and tryptamines <i>via</i> C–H functionalization
strategy activated the C-Br bonds of α-bromo-alkylcarboxylic esters to provide carbon-centered radicals under the catalysis of Ir(iii) photocatalyst and coupled with indole derivatives. This methodology displayed wide functional group tolerance and excellent regioselectivity, and was applied to the late-stage functionalization and preparation of indole-containing hybrids.