Photocatalytic organic transformations utilizing ruthenium and iridium complexes have garnered significant attention due to the access they provide to new synthetic spaces through new reaction mechanisms. A survey of the photophysical data and the diversity of transformations that may be accomplished utilizing commercially available photocatalysts is contained herein.

A review. Transition metal catalyzed decarboxylative allylations, benzylations, and interceptive allylations are reviewed.

Catalytic access to thermodynamically less stable Z-alkenes has recently received considerable attention. These approaches have relied upon kinetic control of the reaction to arrive at the thermodynamically less stable geometrical isomer. Herein, we present an orthogonal approach which proceeds via photochemically catalyzed isomerization of the thermodynamic E-alkene to the less stable Z-isomer which occurs via a photochemical pumping mechanism. We consider two potential mechanisms. Importantly, the reaction conditions are mild, tolerant, and operationally simple and will be easily implemented.

Polyfluorinated aromatics are essential to materials science as well as the pharmaceutical and agrochemical industries and yet are often difficult to access. This Communication describes a photocatalytic hydrodefluorination approach which begins with easily accessible perfluoroarenes and selectively reduces the C-F bonds. The method allows facile access to a number of partially fluorinated arenes and takes place with unprecedented catalytic activity using a safe and inexpensive amine as the reductant.

No abstract

Strong bis-cyclometalated iridium photoreductants, in combination with a single sacrificial reductant, enable visible-light-promoted reductive activation of a variety of challenging substrates under simple and general reaction conditions.

Multifluorinated biaryls are challenging to synthesize and yet an important class of molecules. Owing to the difficulty associated with selective fluorination, this class of molecules represent a formidable synthetic challenge. An alternative approach to selective fluorination of biaryls is to couple an arene which already possess C–F bonds in the desired location. This strategy has been regularly utilized, relying heavily on traditional cross-coupling strategies which employ organometallics and halides (or pseudohalides) in order to achieve the coupling. Herein, we report conditions for the photocatalytic coupling via the direct functionalization of the C–F bond of a perfluoroarene and C–H bond of the other arene to provide an expedient route to multifluorinated biaryls. The mild conditions and good functional group tolerance enable a broad scope-including access to the anti-Minisci product of basic heterocycles. Finally, we demonstrate the value of the C–F functionalization approach by utilizing the high fluorine content to systematically build complex biaryls that contain between 2–5 Caryl–F bonds via synergistic use of photocatalysis and SNAr chemistry.

This work highlights the role of photocatalyst volume in controlling photoquenching events and is exploited to control the reaction outcomes.