Cu-Catalyzed Arylation of Bromo-Difluoro-Acetamides by Aryl Boronic Acids, Aryl Trialkoxysilanes and Dimethyl-Aryl-Sulfonium Salts: New Entries to Aromatic Amides

Mechanochemical synthesis of aromatic ketones: pyrylium tetrafluoroborate mediated deaminative arylation of amides

A new method has been introduced that is able to tackle the complexities of N-C(O) activation in amide moieties through utilization of pyrylium tetrafluoroborate in a mechanochemical setting, where amide bonds undergo activation and subsequent conversion to biaryl ketones. Due to the employment of a mechanochemical setting, the reaction conforms to green chemistry principles, offering an environmentally friendly approach to traditional amide derivatization techniques that rely on transition metals to achieve further functionalization.

Synthesis of Amides via the Amination of Aldehydes with Hydroxylamines Promoted by TBAF·3H2O

A metal-free, mild, and efficient method for the synthesis of amides has been developed from the amination of aldehydes with hydroxylamines promoted by TBAF·3H2O in the presence of KOH. Control experiments showed that the nitrone was the intermediate of this amination. By this method, a series of amides, biologically active compounds bebenil and a COX inhibitor were obtained in moderate to good yields.

Mechanochemical arylative detrifluoromethylation of trifluoromethylarenes

The stoichiometric defluorinative functionalization of ArCF3 is a conceptually appealing research target. It enables the challenging late-stage functionalization of CF3-containing aromatic molecules and contributes to the remedy of environmental risks resulting from the accumulation of relatively inert ArCF3-containing molecules. Similarly, Ar-CN bond features limit their utilization in cross-coupling reactions. Thus, the employment of benzonitriles in decyanative Suzuki-Miyaura type coupling remains in high demand in the field of C-C bond formation. Herein, we report mechanochemically induced and ytterbium oxide (Yb2O3)-mediated defluorinative cyanation of trifluoromethylarenes. In addition, we describe a facile mechanochemically facilitated and nickel-catalyzed decyanative arylation of benzonitriles to access biphenyls. Combining both processes in a one-pot multicomponent protocol to achieve a concise direct arylative detrifluoromethylation of ArCF3 is described herein. This work is the first hitherto realization of C-C coupling with CF3 as a formal leaving group.

Mechanochemical Defluorinative Arylation of Trifluoroacetamides: An Entry to Aromatic Amides

The amide bond is prominent in natural and synthetic organic molecules endowed with activity in various fields. Among a wide array of amide synthetic methods, substitution on a pre-existing (O)C-N moiety is an underexplored strategy for the synthesis of amides. In this work, we disclose a new protocol for the defluorinative arylation of aliphatic and aromatic trifluoroacetamides yielding aromatic amides. The mechanochemically induced reaction of either arylboronic acids, trimethoxyphenylsilanes, diaryliodonium salts, or dimethyl(phenyl)sulfonium salts with trifluoroacetamides affords substituted aromatic amides in good to excellent yields. These nickel-catalyzed reactions are enabled by C-CF₃ bond activation using Dy₂O₃ as an additive. The current protocol provides versatile and scalable routes for accessing a wide variety of substituted aromatic amides. Moreover, the protocol described in this work overcomes the drawbacks and limitations in the previously reported methods.

Mechanochemical synthesis of aromatic sulfonamides

A three-component Pd-catalysed aminosulfonylation reaction of K₂S₂O₅ and amine with aryl bromides or aromatic carboxylic acids was developed. This strategy was developed to utilise mechanical energy and accommodate primary as well as secondary aliphatic and aromatic amines to provide a new shortcut to a wide range of sulfonamides. Studies on the scope and limitations of the reaction indicated its tolerance of a vast range of functional groups and many structural patterns. The reactions were scaled up to gram quantities.