Diverse synthesis of the C ring fragment of bryostatins via Zn/Cu-promoted conjugate addition of α-hydroxy iodide with enone

A convergent approach to 1,5-hydroxy ketones,the general precursors for constructing the C ring of bryostatins,has been developed via a Zn/Cu-promoted conjugate addition of a-hydroxy iodides with enones.The reaction leads to direct formation of the C21-C22 bond and tolerates diverse functionalities at the C17-,C18-and C24-positions.The approach also enables a more concise synthesis of the known C ring intermediate(10 longest linear steps and 14 total steps),in contrast to its previous synthesis(17 longest linear steps and 22 total steps) in our total synthesis of bryostatin 8.     

Photocatalytic/Cu‐Promoted C−H Activations: Visible‐light‐Induced ortho‐Selective Perfluoroalkylation of Benzamides

A visible‐light‐induced and copper‐promoted perfluoroalkylation of benzamides was successfully developed under the assistance of an 8‐aminoquinoline directing group. It provides a straightforward method for the synthesis of ortho‐perfluoroalkyl‐substituted benzoic acid derivatives. The reaction employs a cheap organic dye eosin Y as the photoredox catalyst and is run under the irradiation of a 26 W fluorescent LED light bulb.