Arylnitration of alkenes by nitration/C–H functionalization cascade using AgNO3 and HOAc

Radical annulation of a designed diene system: access to nitro-benzo[b]azepines

Herein, we describe a novel O₂N˙-triggered ordered addition 7-endo cyclization reaction with excellent chemo- and regioselectivity. With such a strategy, structurally diverse nitro-benzo[b]azepines were prepared with 28 examples. Large-scale operation and handy N-Ts and N-Cbz deprotection reveal the promising utility of this methodology. Mechanistic studies suggest that the reaction proceeds through a radical pathway.

Rapid construction of γ-lactam containing 3,3-disubstituted oxindoles via a silver-catalyzed cascade radical bicyclization reaction

An efficient cascade bicyclization strategy for the construction of γ-lactam containing 3,3-disubstituted oxindole derivatives is described, which enables the sequential assembly of both unactivated and activated double bonds in one pot.

Three-Component Radical Iodonitrosylative Cyclization of 1,6-Enynes under Metal-Free Conditions

A three-component, metal-free radical cascade iodonitrosylative cyclization reaction was described. The nitroso radical was generated from tert-butyl nitrite and triggered the radical addition/cyclization/iodination/oxidation sequences. A variety of 1,6-enynes were tested and proved to be compatible, delivering various highly functionalized hetero- and all-carbon cycles and nitro and vinyl C-I bonds containing pyrrolidines, tetrahydrofuran, and cyclopentane in moderate to excellent isolated yields.

Intramolecular nitration–aminocarbonylation of unactivated olefins: metal-free synthesis of γ-lactams

A novel, metal-free synthesis of valuable γ-lactams through the radical-mediated nitration–aminocarbonylation of unactivated olefins is reported.

Visible-light induced tandem radical cyanomethylation and cyclization of N-aryl acrylamides: access to cyanomethylated oxindoles

A visible-light induced cyanomethylation of N-aryl acrylamides with bromoacetonitrile followed by intramolecular cyclization has been explored.

Addition of nitrogen dioxide to carbon–carbon double bond followed by a cyclization to construct nitromethylated isoquinolinediones

4-(Nitromethyl)isoquinoline-1,3(2H,4H)-diones were synthesized via a tandem nitration/cyclization reaction of N-alkyl-N-methacryloyl benzamides using CO₂ as the nitro source.

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

The synthesis of novel tetrahydroquinolines (THQ) and dihydroquinolines (DHQ) are reported using three practical, scalable synthetic approaches to access highly lipophilic analogues bearing a 6-iodo substituent, each with a different means of cyclisation. A versatile and stable quinolin-2-one intermediate was identified, which could be reduced to the corresponding THQ with borane reagents, or to the DHQ with diisobutylaluminium hydride via a novel elimination that is more favourable at higher temperatures. Coupling these strongly electron-donating scaffolds to electron-accepting moieties caused the resulting structures to exhibit strong fluorescence.

Ag-catalyzed C-H/C-C bond functionalization

Silver, known and utilized since ancient times, is a coinage metal, which has been widely used for various organic transformations in the past few decades. Currently, the silver-catalyzed reaction is one of the frontier areas in organic chemistry, and the progress of research in this field is very rapid. Compared with other transition metals, silver has long been believed to have low catalytic efficiency, and most commonly, it is used as either a cocatalyst or a Lewis acid. Interestingly, the discovery of Ag-catalysis has been significantly improved in recent years. Especially, Ag(i) has been demonstrated as an important and versatile catalyst for a variety of organic transformations. However, so far, there has been no systematic review on Ag-catalyzed C-H/C-C bond functionalization. In this review, we will focus on the development of Ag-catalyzed C-H/C-C bond functionalization and the corresponding mechanism.

Iron-catalyzed addition/cyclization cascade of activated alkenes with alcohols: access to carbonyl substituted quinoline-2,4-diones

Iron-catalyzed radical addition/cyclization cascade of o-cyanoarylacrylamides with alcohols has been developed for the synthesis of carbonyl substituted quinoline-2,4(1H,3H)-diones.

Silver-catalyzed synthesis of 2-arylvinylphosphonates by cross-coupling of β-nitrostyrenes with H-phosphites

An efficient protocol for stereoselective synthesis of vinylphosphonates has been developed via AgNO₃-catalyzed cross-coupling of β-nitrostyrenes with dialkyl H-phosphites under mild conditions.

Copper-catalyzed alkylarylation of activated alkenes using isocyanides as the alkyl source: an efficient radical access to 3,3-dialkylated oxindoles

A novel copper-catalyzed oxidative cyclization of N-arylacrylamides for the synthesis of 3,3-dialkylated oxindoles is described using isocyanides as alkyl radical precursors.

Metal-free nitro-carbocyclization of 1,6-enynes with tBuONO and TEMPO

A novel and convenient metal-free nitration and cyclization of 1,6-enynes has been developed.

Metal-free syntheses of oxindole derivatives via a benzoylation/substitution/desulfonylation/cyclization cascade

A benzoylation/substitution/desulfonylation/cyclization cascade reaction giving oxindole derivatives was reported.

1,2-Alkylarylation of activated alkenes with dual C–H bonds of arenes and alkyl halides toward polyhalo-substituted oxindoles

Alkylarylation of N-arylacrylamides with alkyl halides through selective scission of the C(sp³)–H bond adjacent to halide atoms is presented.