Dicationic oligotelluroxane or mononuclear telluronium cation? Elucidation of true catalytic species and activation mechanism of benzylic carbon-halogen bond

The application of diaryltelluronium cations as a chalcogen bonding organocatalyst was investigated for the Ritter-like reaction using the time-course NMR analysis. The resistance to water of dicationic oligotelluroxanes differed depending...

Ultra-thin g-C3N4/MFM-300(Fe) heterojunctions for photocatalytic aerobic oxidation of benzylic carbon centers

In situ growth of the MFM-300(Fe) on an ultra-thin sheet of graphitic carbon nitride, formed by exfoliation using supercritical CO2, is reported. The resultant composite CNNS/MFM-300(Fe) shows excellent performance in photocatalytic aerobic oxidation of benzylic C–H groups.

Revised (β-phenyl) stereochemistry of ultrapotent μ opioid BU72

In its crystal structure in complex with the μ opioid receptor (μOR), the opioid BU72 exhibits extreme deviations from the expected geometry.1 Three of these involve the phenyl group. There is also unexplained electron density next to the benzylic carbon. Here I show that inverting the benzylic configuration fills this unexplained density and eliminates the phenyl group outliers, along with all but one of the others. I propose that this is the correct structure of BU72.

Hypervalent iodine(III)-mediated decarboxylative acetoxylation at tertiary and benzylic carbon centers

The decarboxylative acetoxylation of carboxylic acids using a combination of PhI(OAc)2 and I2 in a CH2Cl2/AcOH mixed solvent is reported. The reaction was successfully applied to two types of carboxylic acids containing an α-quaternary and a benzylic carbon center under mild reaction conditions. The resulting acetates were readily converted into the corresponding alcohols by hydrolysis.

Conjugation of Vescalagin with Glucose and Phenylpropanoid: Reactions Related to the Insolubilization of Oak Wood Ellagitannins

Vescalagin is an oak wood ellagitannin, which is biosynthesized in sapwood and insolubilized during the conversion of sapwood to heartwood. The insolubilization of this tannin was attributed to the conjugation of cell wall components, such as cellulose and lignin; however, the chemical mechanism is unclear. In this study, we examined the reactions of vescalagin with glucose and sinapylaldehyde as model experiments for the conjugation of vescalagin with cellulose and lignin, respectively. Heating vescalagin with glucose and sinapylaldehyde afforded conjugation products, the structures of which were determined by spectroscopic methods. The condensation of vescalagin with glycerol proceeded at room temperature. These results suggest that the insolubilization of vescalagin is caused by the formation of covalent bonds at the C-1 benzylic carbon of vescalagin with alcohols and α,β-conjugated carbonyl compounds.