Photoredox catalysis and organocatalysis represent two powerful fields of molecule activation that have found widespread application in the areas inorganic organic chemistry, respectively. We merged these to solve problems asymmetric chemical synthesis. Specifically, enantioselective intermolecular alpha-alkylation aldehydes has been accomplished using an interwoven pathway combines both photoredox catalyst Ru(bpy)3Cl2 (where bpy is 2,2'-bipyridine) imidazolidinone organocatalyst. This...

Over the past several decades, organometallic cross-coupling chemistry has developed into one of most reliable approaches to assemble complex aromatic compounds from preoxidized starting materials. More recently, transition metal-catalyzed carbon-hydrogen activation circumvented need for materials, but this approach is limited by a lack practical amination protocols. Here, we present blueprint functionalization via photoredox catalysis and describe utility strategy arene amination. An...

ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTRecent Applications of Organic Dyes as Photoredox Catalysts in SynthesisDavid A. Nicewicz* and Tien M. NguyenView Author Information Department Chemistry, University North Carolina at Chapel Hill, 27599-3290, United States*E-mail: [email protected]Cite this: ACS Catal. 2014, 4, 1, 355–360Publication Date (Web):December 11, 2013Publication History Received21 October 2013Published online20 December inissue 3 January...

Herein, we report half-peak potentials for over 180 organic substrates obtained via cyclic voltammetry. These values are of great use in assessing the thermodynamics an electron-transfer process. In addition, disclose a simple computational method to determine redox substrates.

The development of methods for anti-Markovnikov alkene hydrofunctionalization has been a focal point catalysis research several decades. vast majority work on the control regioselectivity this reaction class hinged transition metal catalyst activation olefin substrates. While progress realized, there are significant limitations to approach, and general solution reactions olefins does not presently exist. In past years, lab focused by single electron oxidation using organic photoredox...

Herein is presented a direct method for the metal-free hydrotrifluoromethylation of alkenes. The relies on single electron oxidation commercially available sodium trifluoromethanesulfinate salt (CF3SO2Na, Langlois reagent) by N-Me-9-mesityl acridinium as photoredox catalyst. Methyl thiosalicylate used substoichiometric H-atom donor aliphatic alkenes, and thiophenol stoichiometric styrenyl substrates. substrate scope transformation broad, including mono-, di- trisubstituted with high...

A direct intramolecular anti-Markovnikov hydroetherification reaction of alkenols is described. By employing catalytic quantities commercially available 9-mesityl-10-methylacridinium perchlorate and 2-phenylmalononitrile as a redox-cycling source H-atom, we report the alkenes with complete regioselectivity. In addition, present results demonstrating that this novel system can be applied to hydrolactonization alkenoic acids.

The emergence of visible light photoredox catalysis has enabled the productive use lower energy radiation, leading to highly selective reaction platforms. Polypyridyl complexes iridium and ruthenium have served as popular photocatalysts in recent years due their long excited state lifetimes useful redox windows, development diverse photoredox-catalyzed transformations. low abundances Ir Ru earth's crust and, hence, cost make these catalysts nonsustainable limited application industrial-scale...

We describe our efforts to understand the key mechanistic aspects of previously reported alkene hydrofunctionalization reactions using 9-mesityl-10-methylacridinium (Mes-Acr+) as a photoredox catalyst. Importantly, we are able detect cation radical intermediates, and confirm that phenylthiyl is capable oxidizing persistent acridinyl in fast process unites catalytic activity hydrogen atom transfer (HAT) manifolds. Additionally, present evidence diphenyl disulfide ((PhS)2) operates on common...

Herein we report a metal-free method for the direct anti-Markovnikov hydroamination of unsaturated amines. Irradiation amine substrates with visible light in presence catalytic quantities easily synthesized 9-mesityl-10-methylacridinium tetrafluoroborate and thiophenol as hydrogen-atom donor furnished nitrogen-containing heterocycles complete regiocontrol. Two examples intermolecular alkene are also disclosed.

A direct, catalytic hydrodecarboxylation of primary, secondary, and tertiary carboxylic acids is reported. The system consists a Fukuzumi acridinium photooxidant with phenyldisulfide acting as redox-active cocatalyst. Substoichiometric quantities Hünig's base are used to reveal the carboxylate. Use trifluoroethanol solvent allowed for significant improvements in substrate compatibilities, method reported not limited bearing α heteroatoms or phenyl substitution. This has been applied direct...

Disclosed herein is a general catalytic system for the intermolecular anti-Markovnikov hydroamination of alkenes. By using an organocatalytic photoredox system, α- and β-substituted styrenes as well aliphatic alkenes undergo hydroamination. Heterocyclic amines were also successfully employed nitrogen nucleophiles, thus providing direct route to heterocyclic motifs common in medicinal agents.

Synthetic transformations that functionalize unactivated aliphatic C–H bonds in an intermolecular fashion offer unique strategies for the synthesis and late-stage derivatization of complex molecules. Herein we report a general approach to functionalization using acridinium photoredox catalyst phosphate salt under blue LED irradiation. This strategy encompasses range valuable transformations, including direct conversions bond C–N, C–F, C–Br, C–Cl, C–S, C–C bonds, all cases alkane substrate as...

Methods for the direct C-H functionalization of aromatic compounds are in demand a variety applications, including synthesis agrochemicals, pharmaceuticals, and materials. Herein, we disclose construction nitriles via using an acridinium photoredox catalyst trimethylsilyl cyanide under aerobic atmosphere. The reaction proceeds at room temperature mild conditions has proven to be compatible with electron-donating -withdrawing groups, halogens, nitrogen- oxygen-containing heterocycles, as well...

Nucleophilic aromatic substitution (SNAr) is a direct method for arene functionalization; however, it can be hampered by low reactivity of substrates and their availability. Herein we describe cation radical-accelerated nucleophilic using methoxy- benzyloxy-groups as nucleofuges. In particular, lignin-derived aromatics containing guaiacol veratrole motifs were competent functionalization. We also demonstrate an example site-selective substitutive oxygenation with trifluoroethanol to afford...

Metal-free, visible light-initiated, living cationic polymerization of 4-methoxystyrene using 2,4,6-tri(p-tolyl)pyrylium tetrafluoroborate and methanol is demonstrated. Molecular weight dispersity are controlled by the concentration methanol. Initial mechanistic analysis suggests that likely serves to regulate propagation cation chain end via reversible transfer in a manner analogous addition-fragmentation polymerization.

Strategies for the direct C–H functionalization of amines are valuable as these compounds comprise a number pharmaceuticals, agrochemicals and natural products. This work describes novel method carbamate-protected secondary via α-carbamyl radicals generated using photoredox catalysis. The use highly oxidizing, organic acridinium catalyst allows oxidation with high redox potentials to give corresponding carbamyl cation radical. Following deprotonation, resultant open-shell species can be...

A metal-free route to PET probes Positron emission tomography (PET) is a widely used imaging technique for medical diagnostics and pharmaceutical development. As the name implies, it requires tracers that emit positrons, typically through labeling with fluorine or carbon radioisotopes. W. Chen et al. devised versatile incorporate radioactive fluoride into aromatic rings. The photochemical method directly substitutes aryl carbon-hydrogen bonds [ 18 F]fluoride so particularly well suited...

A direct catalytic anti-Markovnikov addition of carboxylic acids to alkenes is reported. The catalyst system comprised the Fukuzumi acridinium photooxidant (1) and a substoichiometric quantity hydrogen-atom donor. Oxidizable olefins, such as styrenes, trisubstituted aliphatic alkenes, enamides, can be employed along with variety afford adducts exclusively. deuterium-labeling experiment lends insight potential mechanism.

A direct method to synthesize lignan cyclobutanes and analogs via photoinduced electron transfer is presented. variety of oxygenated alkenes are employed furnish terminal or substituted cyclobutane adducts with complete regiocontrol, yielding cycloadducts trans stereochemistry. Key minimizing competing cycloreversion the inclusion an aromatic relay (ER). This has been adapted synthesis natural products magnosalin pellucidin A.

Direct C–H functionalization of aromatic compounds is a useful synthetic strategy that has garnered much attention because its application to pharmaceuticals, agrochemicals, and late-stage reactions on complex molecules. On the basis previous methods disclosed by our lab, we sought develop predictive model for site selectivity extend this aryl chemistry selected set heteroaromatic systems commonly used in pharmaceutical industry. Using electron density calculations, were able predict direct...