Reagent-Controlled Highly Stereoselective Difluoromethylation: Efficient Access to Chiral α-Difluoromethylamines from Ketimines.

A reagent-controlled highly stereoselective reaction between (S)-difluoromethyl phenyl sulfoximine 1 and imines is reported, and this synthetic method provides a variety of enantiomerically enriched α-difluoromethyl amines. The main pros of this approach include high efficiency, high stereoselectivity, and a broad substrate scope, which is probably achieved through a non-chelating transition state.

Dynamic Kinetic Resolution-Enabled Highly Stereoselective Nucleophilic Fluoroalkylation to Access Chiral ß-Fluoro Amines.

ß-Fluorinated amine is highly desirable for biological and pharmaceutical science, because replacing a C-H bond with a C-F bond can change the physical and chemical properties of the parent molecule to a large extent but not significantly alter its overall geometry. Herein, the highly stereoselective nucleophilic monofluoromethylation of imines have been developed. It is proposed that the chelated transition state enables the chiral induction by the dynamic kinetic resolution of the chiral α-fluoro carbanions.

Divergent S- and C-Difluoromethylation of 2-Substituted Benzothiazoles.

Two unprecedented and complementary synthetic strategies for S- and C-difluoromethylation of 2-substituted benzothiazoles have been developed by taking advantage of the remarkably different reactivity of CF2H- and 2-PySO2CF2- nucleophiles. A variety of structurally diverse difluoromethyl 2-isocyanophenyl sulfides and 2-difluoromethylated benzothiazoles were synthesized with these two new synthetic protocols.

Electrochemical oxidation induced intermolecular aromatic C-H imidation.

The dehydrogenative aryl C-H/N-H cross-coupling is a powerful synthetic methodology to install nitrogen functionalities into aromatic compounds. Herein, we report an electrochemical oxidation induced intermolecular cross-coupling between aromatics and sulfonimides with high regioselectivity through N-radical addition pathway under external-oxidant-free and catalyst-free conditions. A wide variety of arenes, heteroarenes, alkenes and sulfonimides are applicable scaffolds in this transformation. In addition, aryl sulfonamides or amines (aniline derivatives) can be obtained through different deprotection process. The cyclic voltammetry mechanistic study indicates that the N-centered imidyl radicals are generated via proton-coupled electron transfer event jointly mediated by tetrabutylammonium acetate and anode oxidation process.

Self-Sacrificial Template-Directed Vapor-Phase Growth of MOF Assemblies and Surface Vulcanization for Efficient Water Splitting.

Direct use of metal-organic frameworks (MOFs) with robust pore structures, large surface areas, and high density of coordinatively unsaturated metal sites as electrochemical active materials is highly desirable (rather than using as templates and/or precursors for high-temperature calcination), but this is practically hindered by the poor conductivity and low accessibility of active sites in the bulk form. Herein, a universal vapor-phase method is reported to grow well-aligned MOFs on conductive carbon cloth (CC) by using metal hydroxyl fluorides with diverse morphologies as self-sacrificial templates. Specifically, by further partially on-site generating active Co3 S4 species from Co ions in the echinops-like Co-based MOF (EC-MOF) through a controlled vulcanization approach, the resulting Co3 S4 /EC-MOF hybrid exhibits much enhanced electrocatalytic performance toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with overpotentials of 84 and 226 mV required to reach a current density of 10 mA cm-2 , respectively. Density functional theory (DFT) calculations and experimental results reveal that the electron transfer between Co3 S4 species and EC-MOF can decrease the electron density of the Co d-orbital, resulting in more electrocatalytically optimized adsorption properties for Co. This study will open up a new avenue for designing highly ordered MOF-based surface active materials for various electrochemical energy applications.