A condensation reaction between quaternary ammonium halide and sulfonate was first successfully applied to the synthesis of the chiral polymers. Reaction of bis(quaternary ammonium halide) with disulfonate afforded a polymer containing ionic bonds in its main chain. The chiral ionic polymers were applied to the asymmetric benzylation of N-diphenylmethylidene glycine tert-butyl ester to prepare (S)-phenylalanine derivatives in high yield with a high level of enantioselectivity.
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http://dx.doi.org/10.1021/ja909972d | DOI Listing |
Sheng Wu Gong Cheng Xue Bao
January 2025
College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China.
In China, the crude oil supply is highly dependent on overseas countries, and thus strengthening crude oil self-sufficiency has become an important issue of the national energy security. Tertiary oil recovery, especially polymer flooding, has been widely applied in large oil fields in China, which can increase the recovery rate by 15%-20% compared with water flooding. However, the widely used oil flooding polymers show poor thermal stability and salinity tolerance, complicated synthesis ways of monomers, and environmental unfriendliness.
View Article and Find Full Text PDFAdv Mater
January 2025
College of Textiles, Donghua University, Shanghai, 201620, China.
Fiber-based artificial muscles are soft actuators used to mimic the movement of human muscles. However, using high modulus oxide ceramics to fabricate artificial muscles with high energy and power is a challenge as they are prone to brittle fracture during torsion. Here, a ceramic metallization strategy is reported that solves the problem of low torsion and low ductility of alumina (AlO) ceramics by chemical plating a thin copper layer on alumina filaments.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Shenzhen Grubbs Institute and Department of Chemistry, Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
ConspectusChiral organosilicon compounds bearing a Si-stereogenic center have attracted increasing attention in various scientific communities and appear to be a topic of high current relevance in modern organic chemistry, given their versatile utility as chiral building blocks, chiral reagents, chiral auxiliaries, and chiral catalysts. Historically, access to these non-natural Si-stereogenic silanes mainly relies on resolution, whereas their asymmetric synthetic methods dramatically lagged compared to their carbon counterparts. Over the past two decades, transition-metal-catalyzed desymmetrization of prochiral organosilanes has emerged as an effective tool for the synthesis of enantioenriched Si-stereogenic silanes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of Science and Technology of China, Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemistry, and Polymer Science and Engineering, 96 Jinzhai Road, 230026, Hefei, CHINA.
Degradable chalcogenide polyesters, e.g., polythioesters (PTEs), typically exhibit improved thermal, mechanical, and optical properties.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States.
In two-dimensional (2D) chiral metal-halide perovskites (MHPs), chiral organic spacers induce structural chirality and chiroptical properties in the metal-halide sublattice. This structural chirality enables reversible crystalline-glass phase transitions in (-NEA)PbBr, a prototypical chiral 2D MHP where NEA represents 1-(1-naphthyl)ethylammonium. Here, we investigate two distinct spherulite states of (-NEA)PbBr, exhibiting either radial-like or stripe-like banded patterns depending on the annealing conditions of the amorphous film.
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