Photocatalytic C2-trifluoroethylation and perfluoroalkylation of 3-substituted indoles using fluoroalkyl halides.

A photocatalytic reactivity platform for the C2-trifluoroethylation and perfluoroalkylation of 3-substituted indoles has been developed. A range of fluoroalkyl halides have been employed as radical precursors under mild, transition-metal-free conditions to access new (per)fluorinated chemical space featuring the indole substructure. This general protocol is also applicable to indole-containing peptides.

Photocatalytic, α-Aminoalkyl Radical-Mediated, Methylene-Extrusive Ring-Closing Transformation of -Alkynyl and -Cyano Acrylamides.

Herein we report a visible-light-induced, α-aminoalkyl radical-mediated cascade reaction of 1,7-enynes that establishes a unique ring-closing enyne transformation pathway which occurs with concomitant loss of a methylene moiety. The α-aminoalkyl radical derived from ,-dimethylaniline was demonstrated to be a traceless promoter of enyne reorganization leading to 4-alkylquinolinones. The reaction can also be extended to nitrile-substituted acrylamide systems, leading to carbostyrils.

Cascade Cyclizations Triggered by Photochemically Generated Carbamoyl Radicals Derived from Alkyl Amines.

We report on a visible light-mediated cascade carbamoylation/cyclization of acrylamides using dihydropyridyl carbamoyl donors derived from alkyl amines. Diversely selected acrylamides including 2-cyano--arylacrylamides, indolyl- and benzimidazolyl acrylamides, and 2-alkynyl--aryl acrylamides participate in this reaction, providing products in good yields. The highlights of this photochemical method include the application of alkyl amine-derived carbamoyl donors, peroxide-free reaction conditions, and a broad scope.

Visible-light mediated, oxygen-promoted regioselective cross-dehydrogenative coupling of coumarins and dimethylanilines.

Herein, we report a regioselective, photocatalytic C3 α-aminoalkylation of coumarins a cross-dehydrogenative coupling of dimethylanilines and coumarins. Molecular oxygen was utilized as the oxidizing agent in this transformation, which exhibits a wide substrate scope and affords the products in good yields. It was established that 4-amino-substituted coumarin reacts a different mechanism compared to coumarin derivatives that are unsubstituted at the 4-position.

Photocatalytic, Intermolecular Olefin Alkylcarbofunctionalization Triggered by Haloalkyl Radicals Generated via Halogen Atom Transfer.

A visible-light-mediated, haloalkyl-radical-initiated, three-component olefin difunctionalization is reported. The application of haloalkyl radicals generated via halogen atom abstraction by α-aminoalkyl radicals has been demonstrated for accessing a new halogenated chemical space. Overall, the alkylcarbofunctionalization of styrenes was accomplished by employing them as (poly)haloalkyl radical acceptors and subsequent C-C bond formation with quinoxalinones.

Visible light-mediated ring-ablative functionalization of oxazoles: oxidative azidation and demethylative amination.

Photochemical functionalization of alkoxyoxazoles with trimethylsilyl azide and ,-dimethylanilines is described. These C-N bond forming reactions proceed with concomitant oxidative ring-opening assisted by organic dyes as photocatalyst and molecular oxygen, providing access to novel chemical space. Unusual demethylative C-N bond formation in the case of ,-dimethylanilines establishes a new reactivity pattern for these precursors.

Pd-Catalyzed Photochemical Alkylative Functionalization of C═C and C═N Bonds.

The development of excited-state palladium-catalyzed alkylative cyclization of acrylamides and the alkylation of quinoxalinones is described. The application of a variety of primary, secondary, and tertiary unactivated alkyl halides as alkyl radical precursors and the use of a simple catalyst system are the highlights of this reactivity manifold. The reactions exhibit wide scope, occur under mild conditions, and furnish the products in excellent yields.

Visible Light-Mediated Carbamoylation of -Quinone Methides.

We report a photocatalytic approach for the installation of the amide moiety onto -quinone methides. This transformation features a net reductive approach for the generation of carbamoyl radicals from amide-substituted Hantzsch ester derivatives under transition metal-free conditions. This protocol exhibits wide scope and allows access to diarylacetamides employing a C-C bond formation approach.

-graphyne as a promising anode material for Na-ion batteries: a first-principles study.

Lithium-ion batteries (LIBs) have emerged as a technological game-changer. Due to the rising price of lithium and the environmental concerns LIBs pose, their use is no longer viable. Sodium (Na) may be the best contender among the alternatives for replacing lithium.

Visible-Light-Mediated Three-Component Cascade Sulfonylative Annulation.

Visible-light-promoted cascade radical cyclization for the synthesis of sulfonylated benzimidazo/indolo[2,1-]iso-quinolin-6(5)-ones has been reported. The reaction provides transition-metal-free and expeditious access to sulfonylated polyaromatics. The use of sodium metabisulfite as a SO surrogate and the rapid generation of molecular complexity using a three-component photochemical protocol are the salient features of this reaction manifold.

Visible-light-mediated synthesis of α,β-diamino esters coupling of ,-dimethylanilines and glyoxalic oxime ethers.

A visible-light-mediated synthesis of α,β-diamino esters has been developed the cross coupling of ,-dimethylanilines with glyoxalic oxime ethers. This protocol involves the generation of α-aminoalkyl radicals under mild reaction conditions, provides α,β-diamino esters in good to excellent yields, and can be performed on a gram-scale.