Herein, a mild metal-free and efficacious route for the synthesis of biologically important 3-aryl oxindole derivatives is described. Using Lambert salt-initiated hydroarylation of isatin, a diverse array of monoarylated products, symmetrical/unsymmetrical double-arylated products, and deoxygenated hydroarylated products could be synthesized from the single starting substrate in good to excellent yields. A preliminary mechanistic study revealed that the reaction proceeds via a monoarylated product followed by a nucleophilic attack by another electron-rich arene nucleophile under mild conditions. The potential of newly synthesized symmetric/unsymmetric 3,3-disubstituted oxindole, 3-substituted 3-hydroxy oxindoles, 3,3-di­(indolyl)­indolin-2-ones, and α-aryl oxindoles as valuable building blocks is further illustrated.

Silicon‐containing molecules are of great interest with widespread applications in several research areas such as polymer chemistry, materials science, medicinal chemistry, and complex molecule synthesis. Transition‐metal‐free C−H silylation is an essential process because this process is useful in fabricating carbon‐silicon bonds which can be further transformed into a number of other compounds. Since transition‐metal‐catalyzed C−H bond silylation is a developed field, therefore this context only contains transition‐metal‐free pathways for transforming C−H bond to C−Si (Si=SiR3) bond. This review has been further categorized and subcategorized based on intermediates involved and catalysts used during this transformation. This synopsis summarizes recent developments in the area of silicon chemistry with a focus of innovative transition‐metal‐free catalytic silylation using different strategies such as free radical, base promoted, Brønsted acid, Lewis acid, and frustrated Lewis pair.

A regioselective protocol for the synthesis of cyclopropyl derivatives that relies on Brookhart acid-catalyzed dehydrative coupling over substituted cyclopropylcarbinols without rearrangement is reported herein. The reactions proceed promptly at 25 °C with only 2.0 mol % catalyst loading and produce the cyclopropyl derivatives in excellent yields. This method is well tolerated with a vast range of cyclopropylcarbinols including aliphatic cyclopropylcarbinols, where no elimination product was obtained, demonstrating the protocol’s utility. Further, the Hammett correlation suggested the formation of a cyclopropylcarbinyl cation followed by a coupling reaction. An extremely effective gram-scale reaction has also been demonstrated with a high turnover number.

Dedicated to Professor Martin Oestreich on the occasion of his 50 th birthday.

Owing to the importance of carbon-heteroatom in synthetic organic chemistry and pharmaceuticals, developing reliable and catalyst-free methods for their construction exhibits a significant goal of high practical value for modern...