Copper-Catalyzed Direct Propargylation of Polyfluoroarenes with Secondary Propargyl Phosphates

Synthesis of Alkylated Polyfluorobenzenes through Decarboxylative Giese Addition of Aliphatic N-Hydroxyphthalimide Esters with Polyfluorostyrene

Polyfluoroaromatic compounds play crucial roles in medicinal and material science. However, the synthesis of alkylated polyfluoroarenes has been relatively underdeveloped. In this study, we devised a novel decarboxylative coupling reaction between aliphatic N-hydroxyphthalimide esters and polyfluorostyrene, leveraging the photochemical activity of electron donor-acceptor (EDA) complexes. This method offers simple reaction conditions, a broad substrate scope, and excellent functional group tolerance. Furthermore, we have demonstrated the practicality of this protocol through late-stage polyfluoroaryl modification of biologically active molecules using readily available carboxylic acids as starting materials, thus providing an important supplement to the current toolbox for accessing alkylated polyfluoroaryl motifs.

Recent Advances in the Synthesis of Propargyl Derivatives, and Their Application as Synthetic Intermediates and Building Blocks

The propargyl group is a highly versatile moiety whose introduction into small-molecule building blocks opens up new synthetic pathways for further elaboration. The last decade has witnessed remarkable progress in both the synthesis of propargylation agents and their application in the synthesis and functionalization of more elaborate/complex building blocks and intermediates. The goal of this review is to highlight these exciting advances and to underscore their impact.

Collective synthesis of acetylenic pharmaceuticals via enantioselective Nickel/Lewis acid-catalyzed propargylic alkylation

Chiral acetylenic derivatives are found in many bioactive compounds and are versatile functional groups in organic chemistry. Here, we describe an enantioselective nickel/Lewis acid-catalyzed asymmetric propargylic substitution reaction from simple achiral materials under mild condition. The introduction of a Lewis acid cocatalyst is crucial to the efficiency of the transformation. Notably, we investigate this asymmetric propargylic substitution reaction for the development of a range of structurally diverse natural products. The power of this strategy is highlighted by the collective synthesis of seven biologically active compounds: (-)-Thiohexital, (+)-Thiopental, (+)-Pentobarbital, (-)-AMG 837, (+)-Phenoxanol, (+)-Citralis, and (-)-Citralis Nitrile.

Recent advances in the functionalization of polyfluoro(aza)aromatics via C-C coupling strategies

Polyfluoro(aza)aromatic compounds are of interest in various fields of practical applications, such as medicinal and agrochemistry, materials science and advanced technologies. The C-C coupling reactions are known to be a promising synthetic tool to create challenging fluorinated molecules of diverse architectures. In this review, we have summarized the recent advances in the functionalization of polyfluoro(aza)aromatics via both transition metal-catalyzed and metal-free C-C coupling reactions for the period from 2006 to the beginning of 2021. Also, mechanistic features for chemical transformations of fluoroarene scaffolds and new opportunities for practical applications of the designed fluorinated molecules have been highlighted.

Photoredox/palladium co-catalyzed propargylic benzylation with internal propargylic carbonates

The developed photo/palladium dual catalytic system provided a novel route to internal propargylic benzylation products. A radical coupling mechanism between the propargylic radical and benzyl radical was proposed.

Cu-Catalyzed SN2' Substitution of Propargylic Phosphates with Vinylarene-Derived Chiral Nucleophiles: Synthesis of Chiral Allenes

A new Cu-catalyzed enantioselective three-component (i.e., styrenes, B₂pin₂, and propargylic phosphates) allenylation via an S_N2' substitution of propargylic electrophiles with vinylarene-derived chiral nucleophiles is presented. This method provides an efficient and enantioselective approach to access a range of optically pure di-(1,1-), tri-, and tetra-substituted allenes with α-central chirality and axial chirality in excellent chemo-, regio-, diastereo-, and enantioselectivities.

Bifunctional Solid Catalyst for Organic Reactions in Water: Simultaneous Anchoring of Acetylacetone Ligands and Amphiphilic Ionic Liquid "Tags" by Using a Dihydropyran Linker

The use of solid catalysts to promote organic reactions in water faces the inherent difficulty of the poor mass-transfer efficiency of organic substances in water, which is often responsible for insufficient reaction and low yields. To solve this problem, the solid surface can be manipulated to become amphiphilic. However, the introduction of surfactant-like moieties onto the surface of silica-based materials is not easy. By using an accessible dihydropyran derivative as a grafting linker, a surfactant-combined bifunctional silica-based solid catalyst that possessed an ionic liquid tail and a metal acetylacetonate moiety was prepared through a mild Lewis-acid-catalyzed ring-opening reaction with a thiol-functionalized silica. The surfactant-combined silica-supported metal acetylacetone catalysts displayed excellent catalytic activity in water for a range of reactions. The solid catalyst was also shown to be recyclable, and was reused several times without significant loss in activity.

Synthesis of polyfluoroarene-substituted benzofuran derivatives via cooperative Pd/Cu catalysis

A cooperative Pd/Cu-catalyzed dual C–H bond activation of electron-deficient polyfluoroarenes with aryl halides is developed.

N-Propargylation of secondary amines directly using calcium carbide as an acetylene source

A one-pot N-propargylation of secondary amines has been achieved by heating the amine with formaldehyde and calcium carbide in DMSO in the presence of CuCl as a catalyst. Fifteen examples of propargylic tertiary amines, 12 of which are novel, were efficiently prepared in yields of 65–84%. The advantages of the method are broad substrate scope and a simple work-up procedure.