B01J2531/26

Method for stereospecific cycloaddition reaction

Metal-organic frameworks (MOFs) may have Zn(II), Pb(II), and/or Cd(II) as a central metal ion, a 4,4-bipyridylethylene (bpe) ligand as a first ligand; and fumaric acid (fum) and/or oxalic acid (ox) as a second ligand, wherein the 4,4-bipyridylethylene ligands are stacked in the MOF, and wherein a distance between two consecutive 4,4-bipyridylethylene ligands is less than 5 . Cycloadditions, particularly photoinduced [2+2] cycloadditions may be catalyzed by such MOFs, and/or the conversion of photoinduced [2+2] cycloadditions in inventive MOFs may be increased by mechanical force, such as by grinding.

ORDERED MACROPOROUS METAL-ORGANIC FRAMEWORK SINGLE CRYSTALS AND PREPARATION METHOD THEREOF

An ordered macroporous metal-organic framework single crystals and a preparation method therefor. In the method, a three-dimensional structure constructed by polymer microspheres is used as a template; 2-methylimidazole and zinc nitrate, precursors of MOFs, are firstly deposited in the three-dimensional template; the three-dimensional template containing the precursors is soaked in a mixed solution of ammonia water and methanol subsequently, and the three-dimensional template is taken out after crystallization; the three-dimensional template is soaked in an organic solvent to remove the macromolecular three-dimensional template, and the ordered macroporous MOF single crystals is obtained through centrifugal separation. The ordered macroporous MOF single crystals have a basic framework of zeolitic imidazolate framework-8, and structurally include highly-ordered macro-pores whose pore size may be controlled to be between 50 and 2000 nm based on a size of the used template.

HIGH-ACTIVITY DOUBLE-METAL-CYANIDE CATALYST
20210205799 · 2021-07-08 ·

A high-activity double-metal-cyanide catalyst, a method for fabricating the same, and applications of the same are disclosed. An organic complexing ligand, which is formed via mixing fatty alcohols and alicyclic carbonates, is used to generate a high-activity double-metal-cyanide catalyst. The high-activity double-metal-cyanide catalyst includes at least one double-metal-cyanide compound, at least one organic complexing ligand, and an optional functionalized compound. The double-metal-cyanide catalyst of the present invention has a higher activity than the conventional double-metal-cyanide catalysts. The polyols generated by the present invention has an insignificant amount of high-molecular-weight compounds.

Production of SiOC-bonded polyether siloxanes

SiOC-bonded polyether siloxanes are produced by transesterification of alkoxysiloxanes with polyetherols in the presence of trifluoromethanesulfonate as catalyst. The computational total water content of the reactants including alkoxysiloxanes and polyetherols is 5000 ppm by mass, advantageously 300 ppm by mass, preferably 150 ppm by mass, more preferably 100 ppm by mass, in particular 50 ppm by mass. The determination of the individual water contents is performed beforehand, preferably by titration according to Karl Fischer.

Organic zinc catalyst, preparation method thereof, and method for preparing polyalkylene carbonate resin using the catalyst
10836860 · 2020-11-17 · ·

The present invention relates to an organic zinc catalyst which exhibits more improved catalytic activity than conventional organic zinc catalysts during a polymerization process for the preparation of a polyalkylene carbonate resin and is capable of preventing an aggregation phenomenon during a reaction, a method for preparing the same, and a method for preparing a polyalkylene carbonate resin using the organic zinc catalyst. The method for preparing an organic zinc catalyst includes the step of reacting a zinc precursor with a dicarboxylic acid in the presence of a polyether derivative to form a zinc dicarboxylate-based catalyst.

COMPOSITIONS AND METHODS FOR CATALYSTS BASED ON BRIDGED CHIRAL AMIDOPORPHYRINS AND THEIR METAL COMPLEXES
20200330968 · 2020-10-22 · ·

In one aspect, the disclosure relates to a mode of asymmetric induction in radical processes based on enhanced hydrogen-bonding capability and the situation of metal centers in cavity-like chiral environments. Also disclosed is an asymmetric system for stereoselective synthesis of cyclopropane and aziridine derivatives. The disclosed Co(II)-based metalloradical system has been shown to have an unusual capability of controlling both the degree and sense of asymmetric induction in cyclopropanation and aziridination reactions in a systematic manner. The disclosed system is applicable to a broad scope of substrates having diazo or azido moieties and exhibits a remarkable profile of reactivity and selectivity, providing access to cyclopropane diastereomers and aziridine enantiomers in highly enantioenriched forms. Also disclosed are catalysts useful in the disclosed processes. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

Silica-based zinc catalysts, their preparation and use in the alkoxycarbonylation of amines

The present invention relates to silica-based heterogeneous zinc compounds which are suitable as catalysts in the reaction of amines with dialkyl carbonates to produce carbamates. The catalysts have the formula [SiO.sub.2]CH.sub.2CHRXCOOZn[Y], wherein [SiO.sub.2] represents a silica carrier selected from the group consisting of ordered mesoporous silica and irregular amorphous narrow pore silica, R represents a moiety selected from the group consisting of hydrogen, CH.sub.3, and CH.sub.2CH.sub.3, preferably hydrogen, X is an aliphatic chain of 2 to 11 carbon atoms that optionally comprises ether moieties and [Y] represents a mono anion. The invention is also directed towards a method for the preparation of the aforementioned compounds and towards method for the alkoxycarbonylation of amines.

REDUCTION BY A SILANE IN THE PRESENCE OF ZINC CATALYST
20240010585 · 2024-01-11 ·

The present invention relates to the field of organic synthesis. More specifically, it concerns a process for the selective reduction of a C.sub.3-C.sub.70 substrate containing one or more carbonyl or carboxylic functional groups into the corresponding 5 alcohol diol, or polyalcohol in the presence of a silane and at least one catalyst or pre-catalyst in the form of a zinc complex. The Zinc complex of formula (I) or (II) is also part of the invention.

Catalysts

The present invention relates to the field of polymerisation catalysts, and systems comprising these catalysts for polymerising carbon dioxide and an epoxide, a lactide and/or lactone, and/or an epoxide and an anhydride. The catalyst is of formula (I): ##STR00001##
wherein at least one of M.sub.1 or M.sub.2 is selected from Ni(II) and Ni(III)-X. A process for the reaction of carbon dioxide with an epoxide; an epoxide and an anhydride; and/or a lactide and/or a lactone in the presence of the catalyst is also described.

Magnetically-recoverable catalysts for depolymerization

The present invention relates, in part, to methods for depolymerizing a polymer, in which the method includes use of a magnetic catalyst. The magnetic catalyst can include, e.g., a ore-shell particle, such as a particle having a magnetic core and a shell including a metal-organic framework.