Crucial for this transformation is the addition of sodium iodide, which provides in situ more active alkyl iodides. In the presence of a Rh(I)-DPPP catalyst system diverse esters (81 examples) including industrially relevant acetates from chloro- and dichloromethane can be prepared in a straightforward manner in up to 95% isolated yield. The used ligand not only affects the selectivity of the carbonylation
Photoinduced Specific Acylation of Phenolic Hydroxy Groups with Aldehydes
作者:Tairin Kawasaki、Naoki Ishida、Masahiro Murakami
DOI:10.1002/anie.202008897
日期:2020.10.5
specifically acylate phenolic hydroxyl groups through a radical pathway. When a mixture of an aldehyde and a phenol in ethyl acetate is irradiated with blue light in the presence of iridium and nickel bromide catalysts at ambient temperature, phenoxyl and acyl radicals are transiently generated in situ and cross‐couple to furnish an ester. Aliphatic hydroxygroups remain untouched under the reaction conditions