Metal-Free Cascade Formation of Intermolecular C-N Bonds Accessing Substituted Isoindolinones under Cathodic Reduction

Synthesis of 3-sulfonylisoindolin-1-ones from olefinic amides and sodium sulfinates via electrooxidative tandem cyclization

Sulfonyl groups are motifs that are widely found in biologically active compounds and drug molecules, many isolated natural products as well as pharmaceuticals contain sulfonyl groups. Herein, we present the synthesis of sulfonyl-substituted isoindolones by a electrochemical oxidative radical cascade cycloaddition reaction of olefinic amides with sodium sulfite under oxidant- and catalyst-free conditions. Various olefinic amides and sodium sulfinates were compatible and gave the desired products in yields up to 99%.

Cobalt-Catalyzed Chemodivergent Synthesis of Cyclic Amines and Lactams from Ketoacids and Anilines Using Hydrosilylation

Here, commercially available Co2(CO)8 was utilized as an efficient catalyst for chemodivergent synthesis of pyrrolidines and pyrrolidones from levulinic acid and aromatic amines under slightly different hydrosilylation conditions. 1.5 and 3 equiv of phenylsilane selectively yielded pyrrolidone and pyrrolidine, respectively. Various ketoacids and amines were successfully tested. Plausible mechanism involves the condensation of levulinic acid and amine to form an imine, which cyclizes to 3-pyrrolidin-2-one followed by reduction to pyrrolidone. The final reduction of pyrrolidone gave pyrrolidine.

Access to Amides and Lactams via Pyridotriazole as a Transformable Directing Group

Amide and lactam frameworks were synthesized via an efficient two-step strategy. In this protocol, pyridotriazoles were first treated with isocyanates to form the corresponding amides, which were found to be sufficiently reactive to undergo subsequent intramolecular N-H insertion in the absence of any additional reagents or catalysts.

Electrochemical-Induced Cascade Reaction of 2-Formyl Benzonitrile with Anilines: Synthesis of N-Aryl Isoindolinones

An electrochemical initiated tandem reaction of anilines with 2-formyl benzonitrile has been developed. Thus, unprecedented 3-N-aryl substituted isoindolinones have been conveniently achieved by constant current electrolysis in a divided cell using catalytic amount of electricity and supporting electrolyte and a Pt-cathode as working electrode. The origin of the electrochemical activation as well as the mechanism of the subsequent chemical cascade reactions have been investigated by DFT calculations.

Ethyl 5-Formyl-1-(pyridin-3-yl)-1H-1,2,3-triazole-4-carboxylate: Synthesis, Crystal Structure, Hirshfeld Surface Analysis, and DFT Calculation

For the first time, 5-formyl-1-(pyridin-3-yl)-1H-1,2,3-triazole-4-carboxylate was synthesized via a two-step scheme. The molecular structure of the compound was determined by a single-crystal X-ray diffraction analysis. The Hirshfeld surface analysis was used to study various intermolecular interactions. The crystalline structure is marked by the presence of three types of π-interactions (n→π*, lp···π, and π···π) between the -C(H)=O group and triazole rings. The compound is a versatile polyfunctional building block for construction of annulated 1,2,3-triazoles.

Cathodic Regioselective Coupling of Unactivated Aliphatic Ketones with Alkenes

A regioselective coupling of aliphatic ketones with alkenes has been realized by cathodic reduction. This reaction enables the formation of ketyl radicals and the activation of challenging alkenes under mild electrolysis conditions, providing an effective protocol for accessing diverse tertiary alcohols with substrate-dependent regioselectivity. The practicability of this reaction is demonstrated by scale-up experiments. The hydrogen source for the products, the migration isomerization of allylarenes, and the applicability of internal alkenes are demonstrated by control experiments.

Transition metal-free advanced synthetic approaches for isoindolinones and their fused analogues

The transition metal-free synthetic protocols of isoindolinone and its fused analogues are highlighted in this review since 2007 to 2021.