Allylic Amination of Highly Substituted Alkenes Enabled by Photoredox Catalysis and Cu(II)-Mediated Radical-Polar Crossover.

Allylic amination reactions enable the conversion of alkene feedstocks into value-added products with significant synthetic versatility. Here we describe a method for allylic amination involving photoredox activation and Cu(II)-mediated radical-polar crossover. A range of structurally varied allylic amines can be accessed using this strategy.

Metallaphotoredox: The Merger of Photoredox and Transition Metal Catalysis.

The merger of photoredox catalysis with transition metal catalysis, termed metallaphotoredox catalysis, has become a mainstay in synthetic methodology over the past decade. Metallaphotoredox catalysis has combined the unparalleled capacity of transition metal catalysis for bond formation with the broad utility of photoinduced electron- and energy-transfer processes. Photocatalytic substrate activation has allowed the engagement of simple starting materials in metal-mediated bond-forming processes.

Copper-Mediated Radical-Polar Crossover Enables Photocatalytic Oxidative Functionalization of Sterically Bulky Alkenes.

Oxidative heterofunctionalization reactions are among the most attractive methods for the conversion of alkenes and heteroatomic nucleophiles into complex saturated heterocycles. However, the state-of-the-art transition-metal-catalyzed methods to effect oxidative heterofunctionalizations are typically limited to unhindered olefins, and different nucleophilic partners generally require quite different reaction conditions. Herein, we show that Cu(II)-mediated radical-polar crossover allows for highly efficient and exceptionally mild photocatalytic oxidative heterofunctionalization reactions between bulky tri- and tetrasubstituted alkenes and a wide variety of nucleophilic partners.

Oxidase reactions in photoredox catalysis.

The nature of the terminal oxidant in oxidation reactions is an important reaction variable that can profoundly impact the mechanism, efficiency, and practicality of a synthetic protocol. One might reasonably categorize catalytic oxidation reactions into either "oxygenase" type reactions, in which the oxidant serves as an atom- or group-transfer reagent, or "oxidase" type reactions, where the oxidant is involved in catalyst turnover but does not become structurally incorporated into the product. As the field of photoredox catalysis has matured over the past decade, many successful oxygenase-type photoreactions have been reported.

Tandem copper and photoredox catalysis in photocatalytic alkene difunctionalization reactions.

Oxidative alkene difunctionalization reactions are important in synthetic organic chemistry because they can install polar functional groups onto simple non-polar alkene moieties. Many of the most common methods for these reactions rely upon the reactivity of pre-oxidized electrophilic heteroatom donors that can often be unstable, explosive, or difficult to handle. Herein, we describe a method for alkene oxyamination and diamination that utilizes simple carbamate and urea groups as nucleophilic heteroatom donors.

Photocatalytic Oxyamination of Alkenes: Copper(II) Salts as Terminal Oxidants in Photoredox Catalysis.

A photocatalytic method for the oxyamination of alkenes using simple nucleophilic nitrogen atom sources in place of prefunctionalized electrophilic nitrogen atom donors is reported. Copper(II) is an inexpensive, practical, and uniquely effective terminal oxidant for this process. In contrast to oxygen, peroxides, and similar oxidants commonly utilized in non-photochemical oxidative methods, the use of copper(II) as a terminal oxidant in photoredox reactions avoids the formation of reactive heteroatom-centered radical intermediates that can be incompatible with electron-rich functional groups.