Biomass is an important feedstock for the renewable production of fuels, chemicals, and energy. As of 2005, over 3% of the total energy consumption in the United States was supplied by biomass, and it recently surpassed hydroelectric energy as the largest domestic source of renewable energy. Similarly, the European Union received 66.1% of its renewable energy from biomass, which thus surpassed the total combined contribution from hydropower, wind power, geothermal energy, and solar power. In addition to energy, the production of chemicals from biomass is also essential; indeed, the only renewable source of liquid transportation fuels is currently obtained from biomass.

The Catalytic Valorization of Lignin for the Production of Renewable Chemicals

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

Pick your Pd partners: A number of catalytic systems have been developed for palladium-catalyzed CH activation/CC bond formation. Recent studies concerning the palladium(II)-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle are discussed (see scheme), and the versatility and practicality of this new mode of catalysis are presented. Unaddressed questions and the potential for development in the field are also addressed.

In the past decade, palladium-catalyzed CH activation/CC bond-forming reactions have emerged as promising new catalytic transformations; however, development in this field is still at an early stage compared to the state of the art in cross-coupling reactions using aryl and alkyl halides. This Review begins with a brief introduction of four extensively investigated modes of catalysis for forming CC bonds from CH bonds: PdII/Pd0, PdII/PdIV, Pd0/PdII/PdIV, and Pd0/PdII catalysis. A more detailed discussion is then directed towards the recent development of palladium(II)-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle. Despite the progress made to date, improving the versatility and practicality of this new reaction remains a tremendous challenge.

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Palladium(II)-catalyzed C-H activation/C-C cross-coupling reactions: versatility and practicality.

s, or keywords if they used Heck-type chemistry in their syntheses, because it became one of basic tools of organic preparations, a natural way to

http://aether.cmi.ua.ac.be/artikels/Artikels%20Gitte/Artikels/Reviews/Heck%20reactie%20Beletskaya%20%20Chem.%20Rev.%20003009.pdf

The heck reaction as a sharpening stone of palladium catalysis.

Catalytic dehydrogenative cross-coupling: forming carbon-carbon bonds by oxidizing two carbon-hydrogen bonds

Ruthenium-Catalyzed Reactions for Organic Synthesis.

The metabolism of amines is governed by a variety of enzymes such as amine oxidase, flavoenzyme, and cytochrome P-450. A wide variety of compounds are produced such as ammonia and alkaloids in selective and clean oxidation reactions that proceed under mild reaction conditions. Simulation of the functions of these enzymes with simple transition metal complex catalysts may lead to the discovery of biomimetic, catalytic oxidations of amines and related compounds. Indeed, metal complex catalyzed oxidations have been found to proceed with high efficiency. The first section of this review discusses the dehydrogenative oxidations of amines with transition metal catalysts by transition metal catalysts that simulate amine oxidase. The second section highlights the catalytic oxidation of secondary amines to nitrones by simulation of flavoenzymes. The third section describes the simulation of the function of cytochrome P-450 with lowvalent ruthenium complexes and peroxides. Biomimetic ruthenium-catalyzed oxidations of tertiary amines, secondary amines, and other substrates such as amides, β-lactams, nitriles, alcohols, alkenes, ketones, and even nonactivated hydrocarbons can be performed selectively under mild conditions. These three general approaches provide highly useful strategies for synthesis of fine chemicals and biologically active compounds such as alkaloids, amino acids, and β-lactams.

Synthetic Aspects of Metal‐Catalyzed Oxidations of Amines and Related Reactions

RuCl3-catalyzed oxidative cyanation of tertiary amines with sodium cyanide under molecular oxygen (1 atm) at 60 °C gives the corresponding α-aminonitriles, which are versatile synthetic intermediates of various compounds such as amino acids and unsymmetrical 1,2-diamines, in excellent yields. This reaction is clean and should be an environmentally benign and useful process.

Aerobic Ruthenium-Catalyzed Oxidative Cyanation of Tertiary Amines with Sodium Cyanide

Simulation of the function of cytochrome P-450 with low valent ruthenium complex catalysts leads to the discovery of biomimetic, catalytic oxidation of various substrates selectively under mild conditions. The reactions discussed in this tutorial review are simple, clean, and practical. The principle of these reactions is fundamental and gives wide-scope and environmentally benign future practical methods.

Ruthenium catalyzed biomimetic oxidation in organic synthesis inspired by cytochrome P-450

Ruthenium-catalyzed oxidative cyanation of tertiary amines with molecular oxygen in the presence of sodium cyanide and acetic acid gives the corresponding α-aminonitriles, which are highly useful intermediates for organic synthesis. The reaction is the first demonstration of direct sp3 C−H bond activation α to nitrogen followed by carbon−carbon bond formation under aerobic oxidation conditions. The catalytic oxidation seems to proceed by (i) α-C−H activation of tertiary amines by the ruthenium catalyst to give an iminium ion/ruthenium hydride intermediate, (ii) reaction with molecular oxygen to give an iminium ion/ruthenium hydroperoxide, (iii) reaction with HCN to give the α-aminonitrile product, H2O2, and Ru species, (iv) generation of oxoruthenium species from the reaction of Ru species with H2O2, and (v) reaction of oxoruthenium species with tertiary amines to give α-aminonitriles. On the basis of the last two pathways, a new type of ruthenium-catalyzed oxidative cyanation of tertiary amines with H2O2...

Ruthenium-catalyzed oxidative cyanation of tertiary amines with molecular oxygen or hydrogen peroxide and sodium cyanide: sp3 C-H bond activation and carbon-carbon bond formation.

Shun-Ichi Murahashi

Papers

Ruthenium-Catalyzed Reactions for Organic Synthesis.

Synthetic Aspects of Metal‐Catalyzed Oxidations of Amines and Related Reactions

Aerobic Ruthenium-Catalyzed Oxidative Cyanation of Tertiary Amines with Sodium Cyanide

Ruthenium catalyzed biomimetic oxidation in organic synthesis inspired by cytochrome P-450

Ruthenium-catalyzed oxidative cyanation of tertiary amines with molecular oxygen or hydrogen peroxide and sodium cyanide: sp3 C-H bond activation and carbon-carbon bond formation.