Abstract Current polyamide lithium extraction nanofiltration membranes are susceptible to chlorine degradation and/or low permeance, two problems that hard reconcile. Here we simultaneously circumvented these by designing a quaternized-spiro piperazine monomer and translating its beneficial properties into large-area (1 × 2 m ) via interfacial polymerization with trimesoyl chloride. The quaternary ammonium spiral conformation of the confer more positive charge free volume membrane, leading...

Abstract Liquid crystal polymers (LCPs) have gained tremendous attention in recent years due to their great potentials from fabrication of responsive actuators and sensors construction intelligent soft robotic light modulators. However, conventional LCPs with permanent cross‐links present tedious unmodifiable stimuli‐responsiveness. Recently, dynamic bonds capable reversibly break reform been integrated into LCP, imparting intrinsic characteristics. The LCP possesses unprecedented diverse...

Abstract N-Glycosylated heterocycles play important roles in biological systems and drug development. The synthesis of these compounds heavily relies on ionic N-glycosylation, which is usually constrained by factors such as labile glycosyl donors, precious metal catalysts, stringent conditions. Herein, we report a dehydroxylative radical method for synthesizing N -glycosides leveraging copper metallaphotoredox catalysis, stable readily available 1-hydroxy carbohydrates are activated direct...

A one-pot protocol for the construction of fluoroalkylated isoxazoles directly from commercially available amines and alkynes is described. The reaction scalable, operationally simple, regioselective, mild, tolerant a broad range functional groups. As such, it could be viewed as "click synthesis" isoxazoles. Preliminary mechanistic investigations reveal that transformation involves an unprecedented Cu-catalyzed cascade sequence involving RfCHN2.

Abstract New methods for enhancing the efficiency of peptide cyclization, and fine‐tuning conformations cyclic peptides, are valuable from a drug development perspective. Herein stereoselective fluorination is investigated as new strategy achieving these goals. Four vicinal difluorinated analogues natural heptapeptide unguisin A have been efficiently synthesized. The found to adopt dramatically different secondary structures, controlled by fluorine stereochemistry.

We have developed a stereoselective, glycosyl radical-based method for the synthesis of C-alkyl glycosides via photomediated defluorinative gem-difluoroallylation reaction. demonstrate first time that radicals, generated from bromides, can readily participate in radical polar crossover process, affording diverse array gem-difluoroalkene containing C-glycosides. Notable features this include scalability, mild conditions, broad substrate scope, and suitability late-stage modification complex molecules.

Pochonicine, the first naturally occurring polyhydroxylated pyrrolizidine containing an acetamidomethyl group, which was isolated from Pochonia suchlasporia var. TAMA 87, together with its enantiomer and their C-1 and/or C-3 epimers, have been synthesized sugar-derived cyclic nitrones 9D 9L, respectively. An in-depth NMR study showed that both (1)H (13)C spectra of synthetic pochonicines (1D 1L) matched very well those natural pochonicine in D2O, unequivocally determined relative...

This short review describes the development of new reagents and methods for deoxyfluorination phenols alcohols during period 2011 to 2017. Important advances in mechanistic understanding these processes are discussed. The continuing importance chemistry synthesis valuable target molecules is highlighted through case studies including examples 18F-radiosynthesis preparation exotic multifluorinated compounds. 1 Introduction 2 New Deoxyfluorination Reagents 3 Novel Applications ‘Legacy’...

We report for the first time that imidate radical can be efficiently added to glycals generate glycosyl radicals, based on which a general, toxic-reagent-free synthesis of C-glycosides 2-deoxy-2-amino sugars has been developed. Complementary previous strategies, reaction is 1,2-trans-stereoselective and could use aryl alkenes as substrates. The late-stage functionalization density functional theory calculations are reported.

(+)-Steviamine, the enantiomer of natural (−)-steviamine, and its corresponding C5 epimer have been synthesized from d-ribose-derived cyclic nitrone. (−)-Steviamine was found to be first naturally occurring iminosugar that causes any inhibition α-galactosaminidases.

Total synthesis of the proposed structure (−)-hyacinthacine C5 and its epimers at C6 C7 is described. A key step was construction bicyclic pyrrolizidine system by means a nucleophilic addition dithiane to cyclic nitrone followed Cope–House cyclization.

It is demonstrated that difluoromethyl diazomethane (HCF2CHN2) can react with a broad range of carboxylic acids. The reaction convenient, operationally simple, mild, and tolerant variety different functional groups. In sharp contrast, trifluoromethyl (CF3CHN2) fails to acids in most solvents, acetonitrile this reagent instead undergoes an interrupted esterification (a Mumm reaction) yield N-trifluoroethyl imides. This striking example the ability single F-for-H substitution alter pathway was...

A general and efficient method has been developed for the synthesis of sugar-derived azepane nitrones starting from aldohexoses, with an intramolecular condensation aldehyde hydroxylamine as key step. Through this strategy, each aldohexose produced a pair nitrones, which are precursors various iminosugars.

We have identified a new reactivity of copper/diamine catalysis for the reductive ring-cleavage isoxazoles to yield fluoroalkylated enaminones. This protocol has advantage using commercially available reagents, ease setting up, broad tolerance functionality, and is regiospecific free defluorination reduction reducible functional groups. The utility was demonstrated by one-step, regioselective synthesis pyrazole-based drugs such as celecoxib, deracoxib, mavacoxib.

Applications of sugar-containing polymers in lectin recognition, bacterial adhesion, hydrogels, bioimaging, and drug gene delivery.

Utilizing molecular conformation as a controlling factor, epoxide-containing 2-aryl-piperidines can be ring-opened with the reagent combination of TBAF/KHF₂in regioselective and divergent fashion.

A metal-free, photo-mediated method for the synthesis of C2-phosphorylated carbohydrates has been developed, whose reaction mechanism consists reduction a glycosyl radical to anion.

We have developed a dual copper/photoredox-catalyzed approach for the construction of P(O)-N bond from commercially available aromatic amines and P(O)-H compounds. This metallaphotoredox method avoids toxic or corrosive reagents does not require prefunctionalized substrates. The reaction has broad substrate scope is suitable synthesis phosphonamides phosphinamides, thus complementing previous nonphotochemical approaches. amenable to direct modification drug molecules can be conducted on gram scale.

Chiral hydrazone photoswitch features are its high thermal stability and negative photochromy, making it desirable in the fabrication of thermally stable optical device. However, chiral hydrazones capable reversibly inversing chirality is scarcely reported. Herein, a series new switches, HI-1, HI-2 HI-3, were designed synthesized. Due to photoinduced configuration changes, newly synthesized presents surprising inversion upon light stimulation. Photoisomerization light-driven switch molecules...

Stereoselectively fluorinated analogues of the amino acid statine have been efficiently synthesized. The key step is an organocatalytic electrophilic fluorination a chiral β-oxygenated aldehyde, which provided test both diastereoselectivity and chemoselectivity. target were found to adopt unique conformations influenced by fluorine gauche effect, rendering them potentially valuable building blocks for incorporation into bioactive peptides.