Mild Cobalt(III)-Catalyzed Allylative C-F/C-H Functionalizations at Room Temperature.

Sustainable, cobalt-catalyst enabled, synthetically significant C-F/C-H functionalizations were achieved with an ample substrate scope at an ambient temperature of 25 °C, thereby delivering perfluoroallylated heteroarenes. Detailed experimental and computational mechanistic studies on the C-F/C-H functionalizations provided strong support for a facile C-F cleavage.

Full Selectivity Control in Cobalt(III)-Catalyzed C-H Alkylations by Switching of the C-H Activation Mechanism.

Selectivity control in hydroarylation-based C-H alkylation has been dominated by steric interactions. A conceptually distinct strategy that exploits the programmed switch in the C-H activation mechanism by means of cobalt catalysis is presented, which sets the stage for convenient C-H alkylations with unactivated alkenes. Detailed mechanistic studies provide compelling evidence for a programmable switch in the C-H activation mechanism from a linear-selective ligand-to-ligand hydrogen transfer to a branched-selective base-assisted internal electrophilic-type substitution.

Methylenecyclopropane Annulation by Manganese(I)-Catalyzed Stereoselective C-H/C-C Activation.

C-H/C-C functionalizations with methylenecyclopropanes (MCPs) were accomplished with a versatile base-metal catalyst. A robust manganese(I) complex enabled the expedient annulation of MCPs by synthetically meaningful ketimines to deliver, upon one-pot hydroarylation, densely substituted polycylic anilines in a step-economical fashion. Mechanistic studies provided strong support for a facile organometallic C-H manganation, while typical cobalt, ruthenium, rhodium, and palladium catalysts were found completely ineffective.

C-H Alkylations of (Hetero)Arenes by Maleimides and Maleate Esters through Cobalt(III) Catalysis.

Efficient cobalt(III)-catalyzed (hetero)aryl and alkenyl C-H hydroarylations of maleimides and maleate esters have been achieved under remarkably mild reaction conditions. Thus, the versatile cobalt(III) catalyst [Cp*CoI(CO)] showed excellent atom-and step-economy as well as high chemo- and site-selectivity providing expedient access to pharmacologically useful succinimides with wide functional group tolerance.

Iron-catalyzed C-H/N-H activation by triazole guidance: versatile alkyne annulation.

Iron-catalyzed C-H/N-H functionalizations were achieved by the aid of modular triazole amides. The alkyne annulation allowed for the expedient synthesis of valuable isoquinolone scaffolds with high levels of chemo-, site- and regio-selectivities.

Ruthenium(II)-Catalyzed C-H Alkynylation of Weakly Coordinating Benzoic Acids.

C-H alkynylations with weakly coordinating acids were accomplished by the aid of an expedient ruthenium(II) catalysis manifold. The user-friendly C-H alkynylation occurred under mild conditions with the weak base KCO. The versatility of the ruthenium(II) catalysis was reflected by providing step-economical access to phthalides as well as enabling unprecedented decarboxylative ortho-C-H alkynylations.

Photo-induced copper-catalyzed C-H chalcogenation of azoles at room temperature.

Inexpensive copper catalysts enabled direct C-H chalcogenations at ambient temperature by means of photo-induced catalysis. The expedient copper catalysis set the stage for C-S and C-Se bond formation from readily accessible non-volatile elemental chalcogens. The photo-assisted copper catalysis manifold proved suitable for a wide range of substrates with good functional group tolerance and exhibited high catalytic efficacy even at a reaction temperature of 25 °C.

Air-Stable Manganese(I)-Catalyzed C-H Activation for Decarboxylative C-H/C-O Cleavages in Water.

The decarboxylative C-H/C-O functionalization was accomplished by air- and water-tolerant manganese(I) catalysis. The versatile C-H allylation occurred by facile organometallic C-H metalation on indoles, arenes, amino acids and synthetically meaningful aryl ketimines with ample substrate scope and high levels of chemo-, site- and regio-selectivity.

An epidemic of allergic contact dermatitis caused by a new allergen, caprylhydroxamic acid, in moisturizers.

Background: In 2016, dermatologists in Finland suspected contact allergy in several patients using moisturizers under the trade name Apobase®. Following a formulation change, Phenostat™, which is a mixture of phenoxyethanol, caprylhydroxamic acid, and methylpropanediol, was used as a preservative in Apobase® moisturizers in Finland.

Objectives: To confirm the suspected contact allergy to Apobase® cream, oily cream, and/or lotion, and to identify the specific contact allergen and define its optimal patch test concentration.

Ruthenium(II)-Catalyzed C-C Arylations and Alkylations: Decarbamoylative C-C Functionalizations.

Ruthenium(II)biscarboxylate catalysis enabled selective C-C functionalizations by means of decarbamoylative C-C arylations. The versatility of the ruthenium(II) catalysis was reflected by widely applicable C-C arylations and C-C alkylations of aryl amides, as well as acids with modifiable pyrazoles, through facile organometallic C-C activation.

Manganese(I)-Catalyzed Dispersion-Enabled C-H/C-C Activation.

C-H/C-C Functionalizations were achieved with the aid of a versatile manganese(I) catalyst. Thus, an organometallic manganese-catalyzed C-H activation set the stage for silver-free C-H/C-C transformations with ample substrate scope and excellent levels of chemo-, site-, and diastereo-selectivities. The robust nature of the manganese(I) catalysis regime was reflected by the first C-H/C-C functionalization on amino acids under racemization-free reaction conditions.

Dissecting common and divergent molecular pathways elicited by CdSe/ZnS quantum dots in freshwater and marine sentinel invertebrates.

Water ecosystems represent main targets of unintentional contamination of nanomaterials, due to industrial waste or other anthropogenic activities. Nanoparticle insult to living organisms may occur in a sequential way, first by chemical interactions of the material with the target membrane, then by progressive internalisation and interaction with cellular structures and organelles. These events trigger a signal transduction, through which cells modulate molecular pathway in order to respond and survive to the external elicitation.

Ruthenium(II)-Catalyzed C-H Oxygenations of Reusable Sulfoximine Benzamides.

C-H oxygenations of synthetically meaningful sulfoximine benzamides were accomplished by a versatile ruthenium catalysis regime. The ruthenium(II) catalyst was characterized by excellent mono- and chemoselectivity as well as positional selectivity via facile base-assisted intramolecular electrophilic substitution-type (BIES) C-H activation. The synthetic utility of the approach was reflected by high functional group tolerance and sulfoximine removal in a traceless fashion.

Manganese-Catalyzed C-H Alkynylation: Expedient Peptide Synthesis and Modification.

Manganese(I)-catalyzed C-H alkynylations with organic halides occurred with unparalleled substrate scope, and thus enabled step-economical C-H functionalizations with silyl, aryl, alkenyl, and alkyl haloalkynes. The versatility of the manganese(I) catalysis manifold enabled C-H couplings with haloalkynes featuring, among others, fluorescent labels, steroids, and amino acids, thereby setting the stage for peptide ligation as well as the efficient molecular assembly of acyclic and cyclic peptides. A plausible catalytic cycle was proposed.

Iron-Catalyzed C-H Alkynylation through Triazole Assistance: Expedient Access to Bioactive Heterocycles.

Triazole assistance enabled the first iron-catalyzed C-H alkynylation of arenes, heteroarenes, and alkenes. The modular TAM directing group set the stage for a sequential C-H alkynylation/annulation strategy with ample scope, enabling the iron-catalyzed assembly of isoquinolones, pyridones, pyrrolones, and isoindolinones with high levels of chemo-, site-, and regioselectivity.

Joining Two Natural Motifs: Catechol-Containing Poly(phosphoester)s.

Numerous catechol-containing polymers, including biodegradable polymers, are currently heavily discussed for modern biomaterials. However, there is no report combining poly(phosphoester)s (PPEs) with catechols. Adhesive PPEs have been prepared via acyclic diene metathesis polymerization.

Ruthenium(II)-Catalyzed meta C-H Mono- and Difluoromethylations by Phosphine/Carboxylate Cooperation.

Ruthenium(II)-catalyzed meta-selective C-H (di)fluoromethylation was accomplished by phosphine and carboxylate cooperation. The remote C-H functionalization was characterized by ample substrate scope, thereby setting the stage for meta-(di)fluoromethylation through facile C-H cleavage.

Bioorthogonal Diversification of Peptides through Selective Ruthenium(II)-Catalyzed C-H Activation.

Methods for the chemoselective modification of amino acids and peptides are powerful techniques in biomolecular chemistry. Among other applications, they enable the total synthesis of artificial peptides. In recent years, significant momentum has been gained by exploiting palladium-catalyzed cross-coupling for peptide modification.

meta-C-H Bromination on Purine Bases by Heterogeneous Ruthenium Catalysis.

Methods for positionally selective remote C-H functionalizations are in high demand. Herein, we disclose the first heterogeneous ruthenium catalyst for meta-selective C-H functionalizations, which enabled remote halogenations with excellent site selectivity and ample scope. The versatile heterogeneous Ru@SiO catalyst was broadly applicable and could be easily recovered and reused, which set the stage for the direct fluorescent labeling of purines.

Carboxylate-Enhanced Rhodium(III)-Catalyzed Aryl C-H Alkylation with Conjugated Alkenes under Mild Conditions.

Rhodium(III)-catalyzed C-H bond functionalization for the synthesis of β-aryl aldehydes and ketones from (hetero)aryl oximes, pyri(mi)dine, as well as pyrazoles and α,β-unsaturated carbonyl compounds has been developed under exceedingly mild reaction conditions. Thus, the versatile rhodium(III) catalysis features high step- and atom-economy, oxidant-free reaction conditions, and broad substrate scope.

An autonomic self-healing organogel with a photo-mediated modulus.

A new method is described for fabricating autonomic, self-healing, deformable organogels. We combined imidazolium-based poly(ionic liquid) (PIL) and azobenzene-grafted poly(carboxylic acid) (PAA-Azo) in N,N-dimethyl formamide. Further, complexing PIL with unirradiated (trans) or irradiated (cis) PAA-Azo tuned the elastic modulus of the organogel.

Ruthenium(ii)-catalyzed C-H functionalizations on benzoic acids with aryl, alkenyl and alkynyl halides by weak-O-coordination.

C-H arylations of weakly coordinating benzoic acids were achieved by versatile ruthenium(ii) catalysis with ample substrate scope. Thus, user-friendly ruthenium(ii) biscarboxylate complexes modified with tricyclohexylphosphine enabled C-H functionalizations with aryl electrophiles. The unique versatility of the ruthenium(ii) catalysis manifold was reflected by facilitating effective C-H activations with aryl, alkenyl and alkynyl halides.

E4 ligase-specific ubiquitination hubs coordinate DNA double-strand-break repair and apoptosis.

Multiple protein ubiquitination events at DNA double-strand breaks (DSBs) regulate damage recognition, signaling and repair. It has remained poorly understood how the repair process of DSBs is coordinated with the apoptotic response. Here, we identified the E4 ubiquitin ligase UFD-2 as a mediator of DNA-damage-induced apoptosis in a genetic screen in Caenorhabditis elegans.

Synergistic Heterobimetallic Manifold for Expedient Manganese(I)-Catalyzed C-H Cyanation.

The manganese-catalyzed cyanation of inert C-H bonds was achieved within a heterobimetallic catalysis regime. The manganese(I) catalysis proved widely applicable and enabled C-H cyanations on indoles, pyrroles and thiophenes by facile C-H manganesation. The robustness of the manganese catalyst set the stage for the racemization-free C-H cyanation of amino acids with excellent levels of positional and chemo selectivity by the new cyanating agent NCFS.