Search

Herein, we report the synthesis of three indium complexes (1–3) supported by different chelating ligands (L1–L3). The indium metal complexes were characterized by using multinuclear NMR, and their solid-state structures were confirmed by single-crystal X-ray crystallography. The indium complex 1 (5 mol%) effectively reduced nitroarenes in the presence of phenylsilane and NaI. Nitroarenes containing different functionalities were reduced under standard conditions to give the corresponding amines in good yields. [ABSTRACT FROM AUTHOR]

We report here the use of amidophosphine borane {(BH₃)₂(PPh)₂N(CH₂)C₆H₅} as a competent reducing agent for the hydroboration of ketones and imines under mild and catalyst‐free reaction conditions yielding the corresponding secondary alcohols and secondary amines after aqueous work. Solid amidophosphine boranes, which are easy to synthesize, and easy to handle demonstrated excellent reactivity and functional group tolerance toward a wide variety of ketones and imines, including aromatic, heteroaromatic, and aliphatic derivatives with electron‐withdrawing and electron‐donating substitutions, thus showing excellent chemoselectivity. [ABSTRACT FROM AUTHOR]

An efficient and one‐step synthesis of quinazolinones using 2‐aminobenzamide and benzylamine in DMSO under external catalyst‐ and base‐free conditions is reported. A broad substrate scope and environment‐benign mild reaction conditions are the major attributes of this straightforward synthesis. Moreover, the synthesized quinazolinone derivatives were used to produce pharmaceutically active rutaecarpine analogues using a two‐step reaction: N‐alkylation followed by intramolecular cyclization. [ABSTRACT FROM AUTHOR]

The article discusses a method for synthesizing amide bonds using deoxyfluorinated carboxylic acids and pyridinesulfonyl fluoride. The authors optimized the reaction conditions and explored the substrate scope, demonstrating the versatility and utility of their method. They also showcase the application of this methodology in the synthesis of a challenging ester-linked compound and a tetrapeptide. The research was supported by various funding sources, and there are no conflicts of interest to declare. This article provides valuable information for researchers in the field of medicinal chemistry and organic synthesis. [Extracted from the article]

Glycosylation, the chemical reaction of linking sugar molecules to create complex carbohydrates, plays a crucial role in diverse biological processes and medicinal applications. Over the past decade, significant advancements have been made in glycosylation methodologies, enabling the efficient synthesis of complex oligosaccharides with high stereoselectivity and yield. This review article compiles the studies of key advances in glycosylation techniques that have emerged between 2000 and 2023 on the synthesis and activation of glycosyl fluorides. These methodologies cover a variety of catalysts, solvents, and strategies for glycosyl fluoride activation, including the use of metal catalyst, Lewis's acid catalysts, specific solvent systems, and innovative fluorinating reagents. We provide a comprehensive overview of the strategies, mechanisms, and applications of these methodologies, highlighting their contributions to carbohydrate chemistry. [ABSTRACT FROM AUTHOR]

A practical approach for the α-stereoselective synthesis of deoxyglycosides using cooperative Brønsted acid-type organocatalysis has been developed. The method is tolerant of a wide range of glycoside donors and acceptors, and its versatility is exemplified in the one-pot synthesis of a trisaccharide. Mechanistic studies suggest that thiourea-induced acid amplification of the chiral acid via H-bonding is key for the enhancement in reaction rate and yield, while stereocontrol is dependent on the chirality of the acid. [ABSTRACT FROM AUTHOR]

We report an efficient synthetic route to the metal-free hydroboration and cyanosilylation of a wide range of alkynyl trifluoromethyl ketones using pinacolborane (4,4,5,5-tetramethyl-1,3,2-dioxaborolane) and trimethylsilyl cyanide under mild reaction conditions at ambient temperature. These highly effective hydroboration and cyanosilylation reactions lead to the corresponding alkynyl trifluoromethyl propargyl alcohols after hydrolysis. In addition, trifluoromethyl (CF 3 ) group-based pharmaceutically active enflicoxib analogs were synthesized from propargyl alcohol.

We developed an efficient method for synthesizing glycosyl fluorides from glycosyl hemiacetals using benzene-1,3-disulfonyl fluoride ( S2 ) as the fluorinating agent in combination with the base DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) under mild conditions. This approach enabled the successful synthesis of 17 glycosyl fluorides with various functional groups, including disaccharides and deoxysulfates, with yields of up to 99%. The utility of these synthesized glycosyl fluorides was further demonstrated in the synthesis of important O - and C -glycosides.

Vibrational strong coupling (VSC) has recently been shown to change the rate and chemoselectivity of ground-state chemical reactions via the formation of light-matter hybrid polaritonic states. However, the observation that vibrational-mode symmetry has a large influence on charge-transfer reactions under VSC suggests that symmetry considerations could be used to control other types of chemical selectivity through VSC. Here, we show that VSC influences the stereoselectivity of the thermal electrocyclic ring opening of a cyclobutene derivative, a reaction which follows the Woodward-Hoffmann rules. The direction of the change in stereoselectivity depends on the vibrational mode that is coupled, as do changes in rate and reaction thermodynamics. These results on pericyclic reactions confirm that symmetry plays a key role in chemistry under VSC., (© 2020 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

B(C 6 F 5 ) 3 enables the metal-free unprecedented substrate-controlled direct α-stereoselective synthesis of deoxyglycosides from glycals. 2,3-Unsaturated α- O-glycoside products are obtained with deactivated glycals at 75 °C in the presence of the catalyst, while 2-deoxyglycosides are formed using activated glycals that bear no leaving group at C-3 at lower temperatures. The reaction proceeds in good to excellent yields via concomitant borane activation of glycal donor and nucleophile acceptor. The method is exemplified with the synthesis of a series of rare and biologically relevant glycoside analogues.