Site-Selective C-H Oxygenation via Aryl Sulfonium Salts.

Herein, we report a two-step process forming arene C-O bonds in excellent site-selectivity at a late-stage. The C-O bond formation is achieved by selective introduction of a thianthrenium group, which is then converted into C-O bonds using photoredox chemistry. Electron-rich, -poor and -neutral arenes as well as complex drug-like small molecules are successfully transformed into both phenols and various ethers. The sequence differs conceptually from all previous arene oxygenation reactions in that oxygen functionality can be incorporated into complex small molecules at a late stage site-selectively, which has not been shown via aryl halides.

Iridium-catalyzed 1,5-(aryl)aminomethylation of 1,3-enynes by alkenyl-to-allyl 1,4-iridium(i) migration.

A novel multicomponent coupling reaction involving the iridium-catalyzed 1,5-difunctionalization of 1,3-enynes with arylboronic acids and triazinanes is described. A key step in this 1,5-(aryl)aminomethylation reaction is the alkenyl-to-allyl 1,4-iridium(i) migration.

Switchable Synthesis of Z-Homoallylic Boronates and E-Allylic Boronates by Enantioselective Copper-Catalyzed 1,6-Boration.

The enantioselective Cu-catalyzed 1,6-boration of (E,E)-α,ß,γ,δ-unsaturated ketones is described, which gives homoallylic boronates with high enantiomeric purity and unexpectedly high Z-selectivity. By changing the solvent, the outcome can be altered to give E-allylic boronates.

Rhodium-Catalyzed Oxidative C-H Allylation of Benzamides with 1,3-Dienes by Allyl-to-Allyl 1,4-Rh(III) Migration.

The Rh(III)-catalyzed oxidative C-H allylation of N-acetylbenzamides with 1,3-dienes is described. The presence of allylic hydrogens cis to the less substituted alkene of the 1,3-diene is important for the success of these reactions. With the assistance of reactions using deuterated 1,3-dienes, a proposed mechanism is provided. The key step is postulated to be the first reported examples of allyl-to-allyl 1,4-Rh(III) migration.