In this review, we highlight the use of organic photoredox catalysts in a myriad of synthetic transformations with a range of applications. This overview is arranged by catalyst class where the photophysics and electrochemical characteristics of each is discussed to underscore the differences and advantages to each type of single electron redox agent. We highlight both net reductive and oxidative as well as redox neutral transformations that can be accomplished using purely organic photoredox-active catalysts. An overview of the basic photophysics and electron transfer theory is presented in order to provide a comprehensive guide for employing this class of catalysts in photoredox manifolds.

Organic Photoredox Catalysis

N-Heterocyclic Carbenes in Late Transition Metal Catalysis

Asymmetric enamine catalysis.

Reactions that convert carbon–hydrogen (C–H) bonds into carbon–carbon (C–C) or carbon–heteroatom (C–Y) bonds are attractive tools for organic chemists, potentially expediting the synthesis of target molecules through new disconnections in retrosynthetic analysis. Despite extensive inorganic and organometallic study of the insertion of homogeneous metal species into unactivated C–H bonds, practical applications of this technology in organic chemistry are still rare. Only in the past decade have metal-catalyzed C–H functionalization reactions become more widely utilized in organic synthesis.Research in the area of homogeneous transition metal–catalyzed C–H functionalization can be broadly grouped into two subfields. They reflect different approaches and goals and thus have different challenges and opportunities. One approach involves reactions of completely unfunctionalized aromatic and aliphatic hydrocarbons, which we refer to as “first functionalization”. Here the substrates are nonpolar and hydrophobic a...

Weak coordination as a powerful means for developing broadly useful C-H functionalization reactions.

Small-molecule H-bond donors in asymmetric catalysis.

Cyclopropanation of β,γ-Unsaturated α-Keto Esters with Diazo Esters

Synthesis of Rigidified Cyclic Peptides by Ring-Closing Metathesis

Stereocontrolled synthesis of (.+-.)-asperlin and related stereoisomers using an organotitanium reagent

Ni–Al Bimetallic Catalyzed Enantioselective C–H Cyclization

In the silyl Lewis acid-promoted Mukaiyama aldol reaction, the steric and electronic properties of the silyl group on the silyl Lewis acid influence the reaction mechanism and product distribution. When super silyl triflates such as (TMS)3SiOTf and (TES)3SiOTf are used as Lewis acids, the silyl group of the silyl enol ether chemoselectively transfers to the product. The mechanistic details have been investigated using density functional theory (DFT) calculations.

Hisashi Yamamoto

Papers

Cyclopropanation of β,γ-Unsaturated α-Keto Esters with Diazo Esters

Synthesis of Rigidified Cyclic Peptides by Ring-Closing Metathesis

Stereocontrolled synthesis of (.+-.)-asperlin and related stereoisomers using an organotitanium reagent

Ni–Al Bimetallic Catalyzed Enantioselective C–H Cyclization

Chemoselective Silyl Transfer in the Mukaiyama Aldol Reaction Promoted by Super Silyl Lewis Acid.