Indoles are common motifs in functional agricultural and pharmaceutical molecules. Heteroatom alkylation is the most frequently used chemical reaction in the pharmaceutical field. Developing protocols for the nucleophilic substitution of (indol-2-yl)methyl electrophiles is important for functionalizing indoles. There are few studies on the nucleophilic substitution at the 2′-position of the electrophiles without an electron-withdrawing group at the 1-position or substituents at the 2′- and 3-positions, where the existing approaches require high temperatures and long reaction times. In this study, we demonstrated rapid (7–12 s) and mild (25 °C) microflow nucleophilic substitution at the 2′-position of indole derivatives without an electron-withdrawing group at the 1-position and substituents at the 2′- or 3-positions. Comparable batch conditions resulted in a lower yield.
A variety of 2-substituted 3-selanyl-chromenones are readily prepared through a cascade selanylation/cyclization of alkynyl aryl ketones with sulfonoselenoates. This transformation is performed under metal-free conditions and does not require an additional oxidant. It also has the advantage of broad functional group tolerance and scalability.
Hyperpolarized 13C magnetic resonance spectroscopy can provide unique insights into metabolic activity in vivo. Despite the advantages of this technology, certain metabolic pathways such as the tricarboxylic acid (TCA) cycle are more challenging to examine due to the limitations associated with currently available hyperpolarized 13C probes. In this report, we systematically employ computational analyses, synthetic techniques, and in vitro studies to facilitate the design of new chemical probes for the TCA cycle. This platform allows for the rapid identification of probe scaffolds that are amenable to hyperpolarized 13C experimentation. Using these results, we have developed two 13C-labeled chemical probes, [1,4-13C2]-dipropyl succinate and [1,4-13C2]-diallyl succinate, which are employed in hyperpolarized 13C metabolic studies.
A mild and efficient reaction for synthesizing esters from thioamide precursors has been established. This method is accomplished in one pot under mild conditions. The process involves the alkylation and activation of inert thioamides, which leads to the cleavage of stable C–N and C–S bonds, eventually resulting in valuable esters with a broad range of substrates. The transformation can be easily carried out at room temperature using thioamide substrates, reactants, and activating agents. This protocol has been demonstrated by synthesizing important esters with applications.
Carbohydrate-based macrocyclic compounds are of particular interest because of their multifunctionality, their unique structural and physicochemical properties as well as their potential applications in chemistry, biology, and drug discovery. Introducing a molecular photoswitch into the skeleton of glycomacrocycles makes possible the reversible control of properties of the resulting photoswitchable glycomacrocycles by light illumination. Therefore, development of stereoselective synthesis of this class of glycomacrocycles is of great interest. Two new azobenzene-based glycomacrocycles have been synthesized through an intramolecular glycosylation approach. Excellent 1,2-cis stereoselectivity has been achieved for the mannosylation.