AbstractIntramolecular hydroarylation using aryl alkynylphosphonates proceeds smoothly with a gold/silver catalyst in the presence of trifluoromethanesulfonic acid (TfOH) in the 6‐endo mode, thus affording a unique synthetic method for phosphacoumarins having various functional groups, which could be a privileged structure and prevalent scaffold in phosphorus heterocycles.magnified image
<i>anti</i>-Hydroarylation of Activated Internal Alkynes: Merging Pd and Energy Transfer Catalysis
作者:Javier Corpas、Pablo Mauleón、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1021/acs.orglett.0c02281
日期:2020.8.21
electron-poor and electron-rich aryl reagents is reported. This selectivity is achieved through a sequential syn-carbopalladation of the alkyne by an Ar–Pd species, followed by a tandem, Ir-photocatalyzed, counter-thermodynamic E → Z isomerization. The use of ortho-substituted boronic acids enables direct access to pharmaceutically relevant heterocyclic cores via a cascadeprocess. Mechanistic insight
A facile palladium-catalyzed addition/cyclization of (2-hydroxyaryl)boronic acids with alkynylphosphonates has been developed, providing an effective strategy to construct a series of valuable phosphacoumarins. This methodology features excellent regioselectivity and broad substrate tolerance.