Decarboxylative Xanthylation under Photocatalytic Conditions.

Xanthates are widely used in organic synthesis for the construction of various molecules and have numerous applications as bioactive compounds. Here, we present their preparation via a straightforward photocatalytic decarboxylative xanthylation process involving readily available oxime esters and xanthate dimers. This approach provides access to a wide variety of xanthate compounds in moderate to good yields, including xanthates derived from relevant pharmaceutical and bioactive molecules.

Copper-Catalysed Synthesis of (E)-Allylic Organophosphorus Derivatives: A Low Toxic, Mild, Economical, and Ligand-Free Method.

Organophosphorus compounds are fundamental for the chemical industry due to their broad applications across multiple sectors, including pharmaceuticals, agrochemicals, and materials science. Despite their high importance, the sustainable and cost-effective synthesis of organophoshoryl derivatives remains very challenging. Here, we report the first successful regio- and stereoselective hydrophosphorylation of terminal allenamides using an affordable copper catalyst system.

Visible-Light Organic Photosensitizers Based on 2-(2-Aminophenyl)benzothiazoles for Photocycloaddition Reactions.

We have studied 2-(2-aminophenyl)benzothiazole and related derivatives for their photophysical properties in view of employing them as new and readily tunable organic photocatalysts. Their triplet energies were estimated by DFT calculations to be in the range of 52-57 kcal mol, suggesting their suitability for the [2+2] photocycloaddition of unsaturated acyl imidazoles with styrene derivatives. Experimental studies have shown that 2-(2-aminophenyl)benzothiazoles comprising alkylamino groups (NHMe, NHPr) or the native amino group provide the best photocatalytic results in these visible-light mediated [2+2] reactions without the need of any additives, yielding a range of cyclobutane derivatives.

Metal-Free Decarboxylative Allylation of Oxime Esters under Light Irradiation.

Allylation reactions, often used as a key step for constructing complex molecules and drug candidates, typically rely on transition-metal (TM) catalysts. Even though TM-free radical allylations have been developed using allyl-stannanes, -sulfides, -silanes or -sulfones, much less procedures have been reported using simple and commercially available allyl halides, that are used for the preparation of the before-mentioned allyl derivatives. Here, we present a straightforward photocatalytic protocol for the decarboxylative allylation of oxime esters using allyl bromide derivatives under metal-free and mild conditions.

Activation of glycosyl methylpropiolates by TfOH.

Activation of glycosyl methylpropiolates by TfOH was investigated. Armed and superarmed glycosyl donors can be activated by use of 0.2 equivalent TfOH whereas 1.

Photocatalyzed Amination of Alkyl Halides to Access Primary Amines.

We demonstrate that oxime ester derivatives can be used as both a halogen atom transfer (XAT) agent and an imine source under photocatalytic conditions, allowing the radical amination of alkyl halides, resulting in the formation of a broad scope of imines. Hydrolysis of the latter gives direct access to the corresponding primary amines. Mechanistically, the reaction is believed to proceed through the formation of aryl radical intermediates, which are responsible for the activation of alkyl halides via XAT.

Copper-Catalyzed Regio- and Stereoselective Hydrothiolation of Allenamides, Enamides, and Ynamides.

We report a simple protocol for the copper-catalyzed hydrothiolation of N-unsaturated precursors, i.e., allenamides, enamides, and ynamides, under mild conditions.

Photo-Induced Halogen-Atom Transfer: Generation of Halide Radicals for Selective Hydrohalogenation Reactions.

The first photo-mediated process enabling the generation of halide radicals by Halogen-Atom Transfer (XAT) is described. Contrary to radical transformations involving XAT reactivity, which exploit stable carbon radicals, this unique approach uses 1,2-dihaloethanes for the generation of unstable carbon radicals by XAT. These transient radicals then undergo β-scission with release of ethylene and formation of more stable halide radicals which have been used in selective hydrohalogenations of a large number of unsaturated hydrocarbons, including Michael acceptors, unactivated alkenes and alkynes.

PEER simplified chronic pain guideline: Management of chronic low back, osteoarthritic, and neuropathic pain in primary care.

Objective: To develop a clinical practice guideline to support the management of chronic pain, including low back, osteoarthritic, and neuropathic pain in primary care.

Methods: The guideline was developed with an emphasis on best available evidence and shared decision-making principles. Ten health professionals (4 generalist family physicians, 1 pain management-focused family physician, 1 anesthesiologist, 1 physical therapist, 1 pharmacist, 1 nurse practitioner, and 1 psychologist), a patient representative, and a nonvoting pharmacist and guideline methodologist comprised the Guideline Committee.

Synergistic Copper/Enamine Catalysis for the Regio-, Stereo-, and Enantioselective Intermolecular α-Addition of Aldehydes to Allenamides.

We herein describe an intermolecular enantioselective α-addition of aldehydes to allenamides using a dual copper/enamine catalytic system. Highly enantioselective addition of aldehydes was obtained thanks to secondary amine catalysts. The process was found to be highly regio-, stereo-, and enantioselective under mild conditions.

Easy Access to Allylic Sulfones Through Transition-Metal-Free Hydrosulfonylation Of Allenes.

A Brønsted acid-mediated addition of (hetero)aryl and (cyclo)alkyl sodium sulfinates to -allenyl derivatives, which proceeds in water, is described under very smooth conditions. This reaction provided a practical and efficient protocol for the regio- and stereoselective synthesis of allylic sulfones in an atom- and step-economic fashion.

Visible-Light Decatungstate/Disulfide Dual Catalysis for the Hydro-Functionalization of Styrenes.

We describe an efficient photoredox system, relying on decatungstate/disulfide catalysts, for the hydrofunctionalization of styrenes. In this methodology the use of disulfide as a cocatalyst was shown to be crucial for the reaction efficiency. This photoredox system was employed for the hydro-carbamoylation, -acylation, -alkylation, and -silylation of styrenes, giving access to a large variety of useful building blocks and high-value molecules such as amides and unsymmetrical ketones from simple starting materials.

Metal-Catalyzed Intermolecular Hydrofunctionalization of Allenes: Easy Access to Allylic Structures via the Selective Formation of C-N, C-C, and C-O Bonds.

Following a strong regain of interest over the past 20 years in the chemistry of allenes, this "forgotten" family of unsaturated molecules is undergoing a renaissance. In this context, the metal-catalyzed hydrofunctionalization of allenes is nowadays one of the most studied transformations. The latter is of great interest because it opens a way to produce selectively functionalized allylic structures.

Copper-Catalyzed Hydrocarboxylation of -Allenyl Derivatives.

The addition of carboxylic acids to allenes was performed with copper catalysis. This hydrocarboxylation reaction, occurring on the terminal carbon of the allenes, is totally regio- and stereoselective. It represents the first copper-catalyzed example of intermolecular C-O bond formation by allene hydrofunctionalization.

Transition-Metal-Free α-Vinylation of Enolizable Ketones with β-Bromostyrenes.

An α-vinylation of enolizable ketones has been developed by using β-bromostyrenes and a KO tBu/NMP system. β,γ-Unsaturated ketones of E configuration were obtained in excellent yield and selectivity. Further synthetic possibilities are highlighted by one-pot functionalization via trapping of intermediate dienolates with alkyl, allyl, benzyl, and propargyl halides to generate quaternary centers.

Aerobic and Ligand-Free Manganese-Catalyzed Homocoupling of Arenes or Aryl Halides via in Situ Formation of Aryllithiums.

Ligand-free manganese-catalyzed homocoupling of arenes or aryl halides can be carried out under aerobic conditions via the in situ formation of the corresponding aryllithiums. A wide range of biaryls and derivatives has been obtained, and a mechanism involving monomeric manganese-oxo complexes has been proposed on the basis of DFT calculations.

Proteomic Dissection of the Cellulolytic Machineries Used by Soil-Dwelling .

Bacteria of the phylum are regarded as highly efficient carbohydrate metabolizers, but most species are limited to (semi)soluble glycans. The soil species Cytophaga hutchinsonii and Sporocytophaga myxococcoides have long been known as efficient cellulose metabolizers, but neither species conforms to known cellulolytic mechanisms. Both species require contact with their substrate but do not encode cellulosomal systems of cell surface-attached enzyme complexes or the polysaccharide utilization loci found in many other species.

Transition-Metal-Free Synthesis of Biarylmethanes from Aryl Iodides and Benzylic Ketones.

An original metal-free procedure for the synthesis of biarylmethanes is disclosed herein. The reactions occur with high selectivity starting from aryl iodides and benzylic ketones in the presence of superbasic media (CsOH/DMSO). This procedure allows a straightforward access to a wide range of biarylmethane derivatives substituted with electron-withdrawing and -donating substituents.

Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes.

The selective activation of one carbon-fluorine bond in polyfluorinated aromatic molecules or in trifluoromethyl-containing substrates offers the possibility of accessing unique fluorine-containing molecules, which are difficult to obtain by other synthetic pathways. Among various metals, which can undergo C-F activation, lanthanides (Ln) are good candidates as they form strong Ln-F bonds. Lanthanide metals are strong reducing agents with a redox potential Ln/Ln of approximately -2.

Regio- and Stereoselective Copper-Catalyzed Allylation of 1,3-Dicarbonyl Compounds with Terminal Allenes.

Simple ligand-free copper systems were found as efficient catalysts for the addition of 1,3-dicarbonyl compounds to N-allenyl derivatives. This highly regio- and stereoselective reaction has been accomplished in the presence of malonates, 1,3-ketoesters, and 1,3-diketones with good to excellent yields under mild conditions. This methodology represents the first allylation of 1,3-dicarbonyl compounds with allenes catalyzed by copper.

Development and Implementation of a Registry of Patients Attending Multidisciplinary Pain Treatment Clinics: The Quebec Pain Registry.

The Quebec Pain Registry (QPR) is a large research database of patients suffering from various chronic pain (CP) syndromes who were referred to one of five tertiary care centres in the province of Quebec (Canada). Patients were monitored using common demographics, identical clinical descriptors, and uniform validated outcomes. This paper describes the development, implementation, and research potential of the QPR.

Transcriptomic and proteomic analyses of core metabolism in Clostridium termitidis CT1112 during growth on α-cellulose, xylan, cellobiose and xylose.

Background: Clostridium termitidis CT1112 is an anaerobic, Gram-positive, mesophilic, spore-forming, cellulolytic bacterium, originally isolated from the gut of a wood feeding termite Nasusitermes lujae. It has the ability to hydrolyze both cellulose and hemicellulose, and ferment the degradation products to acetate, formate, ethanol, lactate, H2, and CO2. It is therefore ges in gene and gene product expression during growth of C.

Copper-Catalyzed Hydroamination of Terminal Allenes.

The ligand-free copper-catalyzed hydroamination of allenes has been accomplished in the presence of cyclic secondary amines or anilines derivatives. This novel methodology undergoes the selective generation of (E)-allylamines under smooth conditions with total regio- and stereoselectivity.