Tropo' bello! Asymmetric activation of tropos biphenol 1 and Ti(OiPr)4 with cinchonine 2 generates a remarkably effective catalyst in situ for the asymmetric Strecker reaction N-tosyl (Ts) imines under mild conditions. Various substrates including aldimines, aryl alkyl ketoimines, unsymmetrical diaryl ketoimines were investigated, most them exhibited high enantioselectivities (up to 99 % ee) as well reactivities. Supporting information this article is available on WWW...

Synthesis of 2-alkenylquinoline by reductive olefination quinoline N-oxide under metal-free conditions is disclosed. Practically, the reaction could be performed with as starting material via a one-pot, two-step process. A possible mechanism proposed that involves sequential 1,3-dipolar cycloaddition and acid-assisted ring opening followed dehydration

ABSTRACT A hydrophobically associating copolymer was prepared by free‐radical polymerization with acrylamide (AM), acrylic acid (AA), and N ‐allyloctadec‐9‐enamide (NAE) as monomers. The structure characterized Fourier transform infrared spectroscopy, 1 H‐NMR, 13 C‐NMR, scanning electron microscopy. rheological experiments indicated that the possessed superior properties compared partially hydrolyzed polyacryamide. It found an AM/AA/NAE/Tween‐80 system could effectively decrease interfacial...

Here we report a water-soluble acrylamide sulfonate copolymer for inhibiting shale hydrate formation. The copolymer, denoted as PANAA, was synthesized via copolymerization of (AM), N,N-diallylbenzylamine (NAPA), acrylic acid (AA), and 2-(acrylamide)-2-methylpropane-1-sulfonic (AMPS). performance this new hydration investigated the first time. retention ratio apparent viscosity 2 wt % PANAA solution can reach 61.6% at 130 °C further up to 72.2% with 12 000 mg/L NaCl brine. X-ray diffraction...

This study examines the foams generated by three surfactants: sodium dodecyl sulfate (SDS), dodecylbenzenesulfonate (SDBS), and lauryl polyoxyethylene ether (AES). By analyzing hydrogen bond at gas–liquid interface, research provides novel insights into mechanisms which surfactants stabilize foams. Surfactants adsorb establishing bonds with water molecules while simultaneously retarding structural relaxation of water–water within hydration layer. phenomenon can impede drainage during surface...

Abstract An efficient and optically active, bifunctional tetraaza ligand (2 S )‐ N ‐{(1 R ,2 )‐2‐[( )‐pyrrolidine‐2‐carboxamido]‐1,2‐diphenylethyl}pyrrolidine‐2‐carboxamide has been developed for the addition of trimethylsilyl cyanide (TMSCN) to ketones. The catalyst system based on a monometallic titanium complex was found be highly enantioselective provide O ‐TMS cyanohydrins with up 94% ee. A possible transition state proposed explain origin activation asymmetric inductivity.

Abstract A novel water‐soluble polymer was prepared by copolymerization and sulfomethylation using acrylamide (AM) N ‐allylbenzamide (NABI) as raw materials under mild conditions. The effects of ratio AM to NABI, initiator concentration, reaction temperature, pH, monomer concentration on the were studied. sulfonates copolymer characterized infrared (IR) spectroscopy, 1 H NMR elemental analysis, atomic force microscopy (AFM). It found that could achieve up 25%, 30% retention rate viscosity at...

A non-covalent metallogel system with self-healing, deformation recoverable, moldable and bottom-up load-bearing properties was prepared using tetrazolyl derivatives Pd(OAc)₂.

We report here a novel imidazoline functionalized hydrophobically associating copolymer that exhibits excellent rheological properties and outstanding potential for enhanced oil recovery.

We report the fabrication of poly(2-acrylamide-2-methylpropanesulfonic acid) modified SiO2 (SiO2/PAMPS) nanoparticles as plugging agents in water-based muds (WBMs). SiO2/PAMPS were prepared by copolymerization 3-methacryloxypropyltrimethoxysilane-functionalized and 2-acrylamide-2-methylpropanesulfonic acid. These found to exhibit excellent salt tolerance, thermal stability, good compatibilities with polymeric additives commonly used WBMs. The capabilities tested filter cakes on a...

We report the synthesis of biodegradable polyethylene glycol-based ionic liquids which exhibit potential capability for inhibiting shale hydration.

Constructing insensitive high-performance energetic coordination polymers (ECPs) with alkali/alkali-earth metal ions and a nitrogen-rich organic backbone has been proved to be feasible strategy in this work. Six diverse dimensional novel ECPs (compounds 1-6) were successfully synthesized from NaI , CsI CaII SrII BaII triheterocyclic 4,5-bis(tetrazol-5-yl)-2 H-1,2,3-triazole (H3 BTT). All compounds show outstanding stability low sensitivity, the thermal of these are significantly improved as...

Abstract A novel water‐soluble polymer was prepared by binary copolymerization and sulfomethylation using acrylamide (AM) N ‐phenylmaleimide (N‐PMI) as raw materials under mild conditions. Several factors were investigated optimized conditions confirmed in the sulfomethylation. It found that sulfonates copolymer afforded with up to 60% retention rate of apparent viscosity at 85°C; 30.4 mPa s 500 −1 shear 5.028 min; 3.3 times relativity (compared polyacrylamides) obtained 80 g/L NaCl brine;...

A novel strategy to fabricate diverse α-Mn2O3 nanostructures from the nitrogen-rich energetic coordination polymer (ECP) [Mn(BTO)(H2O)2]n (BTO = 1H,1′H-[5,5′-bitetrazole]-1,1′-bis(olate)) has been developed by changing pyrolysis atmosphere. The results show that constituent and calcination environment are vital factors get quite different morphologies of products. When reaction occurs under N2 or O2, rod-shaped mesoporous with a large specific surface 50.2 m2·g–1 monodispersed size 10–20 nm...

A chiral CpRhIII-catalyzed asymmetric C–H activation reaction of N-methoxybenzamides with quinones has been developed to efficiently forge tricyclic hydrophenanthridinone scaffolds in ≤88% yield and ≤94% ee. With this methodology as the key step, an enantioenriched dihydrolycoricidine derivative synthesized 64% overall five steps.

A new multicomponent bifunctional catalytic system based on a titanium complex was used for the efficient enantioselective cyanation of aldehydes. The catalyst readily prepared from tetraisopropyl titanate (Ti(Oi-Pr)4), (S)-6,6'-dibromo-1,1'-bi-2-naphthol (1e), cinchonine (2a), and (1R,2S)-(−)-N-methylephedrine (3b). It revealed that combination 1e, 2a, 3b, Ti(IV) essential in this cyanation. reaction proceeded smoothly presence amount to afford desired cyanohydrins ethyl carbonates moderate...