The merger of transition metal catalysis and photocatalysis, termed metallaphotocatalysis, has recently emerged as a versatile platform for the development of new, highly enabling synthetic methodologies. Photoredox catalysis provides access to reactive radical species under mild conditions from abundant, native functional groups, and, when combined with transition metal catalysis, this feature allows direct coupling of non-traditional nucleophile partners. In addition, photocatalysis can aid fundamental organometallic steps through modulation of the oxidation state of transition metal complexes or through energy-transfer-mediated excitation of intermediate catalytic species. Metallaphotocatalysis provides access to distinct activation modes, which are complementary to those traditionally used in the field of transition metal catalysis, thereby enabling reaction development through entirely new mechanistic paradigms. This Review discusses key advances in the field of metallaphotocatalysis over the past decade and demonstrates how the unique mechanistic features permit challenging, or previously elusive, transformations to be accomplished. Transition metal catalysis is well established as an enabling tool in synthetic organic chemistry. Photoredox catalysis has recently emerged as a method to effect reactions that occur through single-electron-transfer pathways. Here we review the combination of the two to show how this provides access to highly reactive oxidation states of transition metals and distinct activation modes that further enable the synthetic chemist.

The merger of transition metal and photocatalysis

This critical review examines transition metal-catalyzed decarboxylative couplings that have emerged within recent years as a powerful strategy to form carbon–carbon or carbon–heteroatom bonds starting from carboxylic acids. In these reactions, C–C bonds to carboxylate groups are cleaved, and in their place, new carbon–carbon bonds are formed. Decarboxylative cross-couplings constitute advantageous alternatives to traditional cross-coupling or addition reactions involving preformed organometallic reagents. Decarboxylative reaction variants are also known for Heck reactions, direct arylation processes, and carbon–heteroatom bond forming reactions.

Decarboxylative coupling reactions: a modern strategy for C–C-bond formation

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

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Transition Metal-Catalyzed Decarboxylative Allylation and Benzylation Reactions

ConspectusThe ever-present demand for drugs with better efficacy and fewer side effects continually motivates scientists to explore the vast chemical space. Traditionally, medicinal chemists have focused much attention on achiral or so-called “flat” molecules. More recently, attention has shifted toward molecules with stereogenic centers since their three-dimensional structures represent a much larger fraction of the chemical space and have a number of superior properties compared with flat aromatic compounds. Quaternary stereocenters, in particular, add greatly to the three-dimensionality and novelty of the molecule. Nevertheless, synthetic challenges in building quaternary stereocenters have largely prevented their implementation in drug discovery. The lack of effective and broadly general methods for enantioselective formation of quaternary stereocenters in simple molecular scaffolds has prompted us to investigate new chemistry and develop innovative tools and solutions.In this Account, we describe thr...

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Catalytic Enantioselective Construction of Quaternary Stereocenters: Assembly of Key Building Blocks for the Synthesis of Biologically Active Molecules

A medical device having a contact surface exposed repeatedly to bodily tissue is disclosed. The contact surface is coated with a silicone polymer and one or more non-silicone hydrophobic polymers. The preferred medical device is a surgical needle, and the preferred coating is a polydimethylsiloxane and polypropylene wax hydrocarbon mixture. The incorporation of the non-silicone hydrophobic polymer increases the durability of the coating on the device without sacrificing lubricity.

Medical devices having durable and lubricious polymeric coating

Palladium-catalyzed rearrangement of allylic esters of acetoacetic acid to give γ,δ-unsaturated methyl ketones

La decarboxylation-allylation conduit a des cetones homoallyliques pour des β-cetoesters, a des esters allyliques pour des diesters, a des nitriles homoallyliques pour des cyanoesters

Palladium-catalyzed decarboxylation-allylation of allylic esters of α-substituted β-keto carboxylic, malonic, cyanoacetic, and nitroacetic acids

An efficiemt synthetic method of methyl (±)-jasmonate

O-allyl ether as a new protective group for oximes and its palladium-catalyzed deprotection

The terminal double bond of 3,8-nonadienoate was oxidized to methyl ketone with a catalyst system of PdCl2/CuCl/O2 and the internal double bond was reduced to give 8-oxononanoate, which was hydrolyzed to 8-oxononanoic acid. The Kolbe electrolysis of the acid produced 2,15-hexadecanedione in a high yield.

Toshiro Yamada

Papers

Palladium-catalyzed rearrangement of allylic esters of acetoacetic acid to give γ,δ-unsaturated methyl ketones

Palladium-catalyzed decarboxylation-allylation of allylic esters of α-substituted β-keto carboxylic, malonic, cyanoacetic, and nitroacetic acids

An efficiemt synthetic method of methyl (±)-jasmonate

O-allyl ether as a new protective group for oximes and its palladium-catalyzed deprotection

A Simple Synthetic Method for 2,15-Hexadecanedione from a Butadiene Telomer