A highly efficient, Z-selective ring-closing metathesis system for the formation of macrocycles using a stereoretentive, ruthenium-based catalyst supported by a dithiolate ligand is reported. This catalyst is demonstrated to be remarkably active as observed in initiation experiments showing complete catalyst initiation at −20° C. within 10 min. Using easily accessible diene starting materials bearing a Z-olefin moiety, macrocyclization reactions generated products with significantly higher Z-selectivity in appreciably shorter reaction times, in higher yield, and with much lower catalyst loadings than in previously reported systems. Macrocyclic lactones ranging in size from twelve-membered to seventeen-membered rings are synthesized in moderate to high yields (68-79% yield) with excellent Z-selectivity (95%-99% Z).

Some embodiments of the invention include methods of using a compound (e.g., Formula (I)) for the reduction of carbon dioxide to formate by contacting the carbon dioxide with a composition comprising a compound. In certain embodiments, the source of the carbon dioxide is air or is flue gas. Additional embodiments of the invention are also discussed herein.

A process for preparing b-b dimers having anti-UV and antioxidant properties, from p-hydroxycinnamic esters and amides disubstituted in the ortho position with respect to the phenol function and from ketones disubstituted in the ortho position with respect to the phenol, in particular, from sinapic acid esters and amides and ketone analogs. The dimers of formulae (I), (II), (III) and (IV) as obtained by means of the process according to the present disclosure can be used for the production of polymers/plastics (in plastics technology), or for the protection of plants against the cold and as cosmetic or food-processing ingredients, for example. The process may be used to form biobased anti-UV molecules.

Synthetic methods are described herein operable to efficiently produce a wide variety of molecular species through conjugate additions via decarboxylative mechanisms. For example, methods of functionalization of peptide residues are described, including selective functionalization of peptide C-terminal residues. In one aspect, a method of peptide functionalization comprises providing a reaction mixture including a Michael acceptor and a peptide and coupling the Michael acceptor with the peptide via a mechanism including decarboxylation of a peptide reside.

This invention relates generally to olefin metathesis catalyst compounds, to the preparation of such compounds, compositions comprising such compounds, methods of using such compounds, articles of manufacture comprising such compounds, and the use of such compounds in the metathesis of olefins and olefin compounds. The invention has utility in the fields of catalysts, organic synthesis, polymer chemistry, and industrial and fine chemicals industry.

Novel ruthenium complexes of general formula 4

##STR00001##

in which the substituents are defined herein. The present disclosure relates also to methods for preparing such compounds and use thereof as catalysts and/or (pre)catalysts in olefin cross metathesis.

The invention relates to a method for producing a formate, the method including a first step of reacting hydrogen with carbon dioxide, a hydrogen carbonate or a carbonate using a catalyst in the presence of a solvent to form a formate in the reaction liquid, wherein the reaction is a two-phase system in which an organic phase and an aqueous phase are present in a separated state in the solvent, and a base concentration in the reaction is 2.5 mol/L or more.

An oxidative homocoupling method of synthesizing certain 2,2′-bithiophenes from thiophenes using oxygen as the terminal oxidant is disclosed. In non-limiting examples, the method uses oxygen along with a catalytic system that includes palladium, an assistive ligand, and a non-palladium metal additive to catalyze one of the following reactions: ##STR00001## Associated catalytic systems and compositions are also disclosed.

Disclosed are methods of selective hydrodeoxygenation of aromatic compounds by using catalyst systems comprising N-heterocyclic carbene (NHC) and 4-pyridinol-derived pincer ligands and metal complexes containing these ligands.

Disclosed are methods of forming an epimer or a dehydrated isomer of a pyranose monosaccharide or a pyranose saccharide residue in an oligosaccharide or a glycoside.