Direct copolymerization of ethylene with protic comonomers enabled by multinuclear Ni catalysts.

Ethylene/polar monomer coordination copolymerization offers an attractive way of making functionalized polyolefins. However, ethylene copolymerization with industrially relevant short chain length alkenoic acid remain a big challenge. Here we report the efficient direct copolymerization of ethylene with vinyl acetic acid by tetranuclear nickel complexes.

Nickel-Catalyzed Propylene/Polar Monomer Copolymerization.

Nickel complexes bearing bidentate alkylphophine-phenolate ligands were synthesized and applied to the polymerization of propylene and the copolymerization of propylene and polar monomers. Therein, the use of bulky alkyl substituents on the phosphorus atom was crucial for the formation of highly regioregular polypropylenes. Theoretical calculations suggested that the 1,2-insertion of propylene is favored over the 2,1-insertion in these nickel-catalyzed (co)polymerization reactions.

[Expression and localization of FGFR family in squamous cell carcinoma of head and neck].

Purpose: To investigate the expression and localization of FGFR family in squamous cell carcinoma of head and neck (SCCHN) cell lines.

Methods: Total protein was extracted from 10 SCCHN cell lines and the expression of FGFR was detected by Western blot. The localization of FGFR was further demonstrated by immunofluorescence staining in SCC25 and HN4 cell lines.

Overexpression of stathmin/oncoprotein 18 correlates with poorer prognosis and interacts with p53 in oral squamous cell carcinoma.

Purpose: The stathmin/oncoprotein 18 (STMN1) is overexpressed in various human cancers. The aim of our study was to investigate its clinical significance and interaction with p53 in oral squamous cell carcinoma (OSCC).

Materials And Methods: Stathmin expression was assessed by Oncomine, Gene Expression Omnibus (GEO) database, western blotting, and reverse transcription polymerase chain reaction.

Charge Variants of an Avastin Biosimilar Isolation, Characterization, In Vitro Properties and Pharmacokinetics in Rat.

The similarity between a proposed biosimilar product and the reference product can be affected by many factors. This study is designed to examine whether any subtle difference in the distribution of the charge variants of an Avastin biosimilar can affect its in vitro potency and in vivo PK. Here, the acidic, basic and main peak fractions of a biosimilar product were isolated using high-performance cation-exchange chromatography and were subjected to various studies to compare their in vitro properties and in vivo PK profile.

Copolymerization of Ethylene and Polar Monomers by Using Ni/IzQO Catalysts.

The replacement of precious metals in catalysis by earth-abundant metals is currently one of the urgent challenges for chemists. Whereas palladium-catalyzed copolymerization of ethylene and polar monomers is a valuable method for the straightforward synthesis of functionalized polyolefins, the corresponding nickel-based catalysts have suffered from poor thermal tolerance and low molecular weight of the polymers formed. Herein, we report a series of neutral nickel complexes bearing imidazo[1,5-a]quinolin-9-olate-1-ylidene (IzQO) ligands.

A highly efficient and enantioselective intramolecular Cannizzaro reaction under TOX/Cu(II) catalysis.

An asymmetric intramolecular Cannizzaro reaction of aryl and alkyl glyoxals with alcohols has been realized with an unprecedented high level of enantioselectivity, on the basis of a newly developed congested TOX ligand and a gradual liberation protocol of active glyoxals from glyoxal monohydrates. Preliminary results suggested a mechanism of enantioselective addition of alcohols to glyoxals contributing most to the stereoselectivity, other than by the dynamic kinetic resolution of hemiacetal intermediates.

Water as an activator for palladium(II)-catalyzed olefin polymerization.

By a reasonable combination of the Wacker reaction and olefin polymerization processes, water proves to be an excellent activator for the palladium(II)-catalyzed polymerization of ethylene and it provides a safe, environmental-friendly and handy initiator for olefin polymerization. The activity of the olefin polymerization is comparable to reactions catalyzed by the corresponding alkylated cationic palladium complexes.