Direct Acyl Radical Addition to 2<i>H</i>‑Indazoles Using Ag-Catalyzed Decarboxylative Cross-Coupling of α‑Keto Acids

A direct acyl radical addition to 2<i>H</i>-indazoles has been achieved for the first time, where the less-aromatic <i>quinonoid</i> 2<i>H</i>-indazoles readily accepted radical species to the C-3 position. Motivated by the lack of direct acylation strategy for 2<i>H</i>-indazoles, the current method utilizes the radical acceptability of 2<i>H</i>-indazoles, discovering an ambient temperature reaction to provide facile access to a diverse array of 3-acyl-2<i>H</i>-indazoles with three points of structural diversification in 25%–83% yields

Isolation and structural elucidation of a new tadalafil analogue in health supplements: bisprenortadalafil

<p>A new tadalafil analogue was found, along with nortadalafil, using HPLC-DAD during the inspection of a health product sold without official approval. The analogue was separated using a semi-preparative HPLC system and its structure was determined by a combination of mass spectrometry and NMR spectroscopy. The compound was identified as a tadalafil analogue in which the <i>N</i>-methyl group of tadalafil was replaced with a tadalafil precursor moiety. Nuclear Overhauser effect spectroscopy experiments suggested a <i>cis-</i>relationship between the substituents on a piperidine ring in the tadalafil moiety.</p