Modular amino acid amide chiral ligands for enantioselective addition of diethylzinc to aromatic aldehydes

Abstract

Enantioselective addition of diethylzinc to a series of aromatic aldehydes was developed using a modular amino acid amide chiral ligand (2S)-3-phenyl-N-((R)-1-phenyl-ethyl)-2-(tosylamino)propanamide without using titanium complex. The catalytic system employing 10 mol% of 1g was found to promote the addition of diethylzinc (ZnEt 2 ) to a wide range of aromatic aldehydes with electron-donating and electron-withdrawing substituents, giving up to 82% ee of the corresponding secondary alcohol under mild conditions.

Laboratory study of an anti‐temperature and salt‐resistance surfactant‐polymer binary combinational flooding as EOR chemical

“…When the temperature was lower, intramolecular group associations were dominant. As the temperature increased, a large number of associating groups aggregated together to form reversible, physical, supermolecular structures by strong Van der Wall's interactions, and the polymer chains entangled with each other via hydrogen‐bond interactions in the aqueous solution . But the intermolecular interaction is unstable, especially under high temperature, even degradation and molecular chain fractures are likely to occur, resulting in the apparent viscosity reduction.…”

Synthesis and Application of a New Polymeric Surfactant for Improving Oil Recovery: Interfacial Tension, Wettability and Viscosity Studies in Different Salinities

“…By lowering the water-to-oil mobility ratio, the sweep e ciency is improved, and ngering is reduced, and a better sweep e ciency is achieved. For this purpose, employed polymers should possess features such as high molecular weight, suitable resistance to mechanical degradation (shear rate), high salinity tolerance, su cient thermal resistance, and complete water solubility (Alvarado & Manrique 2010; Zhao et al 2015; Gou et al 2011). Hydrolyzed polyacrylamide (HPAM) is a polymer widely used in EOR, but it is highly sensitive to shear rate, temperature, and hard salinity (Deng et al 2014;Wu et al 2012;).…”

“…Simultaneous injection of alkalines-surfactants-polymers (ASP ooding) and surfactants-polymers (SP ooding) have some problems, such as interactions between polymer and surfactant, loss of surfactant through solubilization in the oil phase, or adsorption on the surface (Gou et al 2011;Sheng 2010;Golabi et al 2009; ).…”