An efficient transition-metal/photocatalyst-free visible-light-driven one-pot three-component reaction between thianthrenium salts, carbon disulfide and amines under air atmosphere for the preparation of S -aryl dithiocarbamates is developed.
Efficient, eco-friendly and sustainable access to 3,4-dihydropyrimidin-2(1H)-ones directly from alcohols under microwave and solvent-free conditions has been reported. The practical protocol involves heteropolyanion-based catalyzed oxidation of alcohols to aldehydes with NaNO3 as the oxidant followed by cyclocondensation with dicarbonyl compounds and urea or thiourea in a two-step, one-pot manner. Compatibility with different functional groups, good to excellent yields and reusable catalysts are the main highlights. The utilization of alcohols instead of aldehydes is a valid and green alternative to the classical Biginelli reaction.
The efficient, one-pot access to the transamidation of 8-aminoquinoline (8-AQ), notorious for its harsh removal conditions, has been widely employed as an auxiliary in C–H functionalization reactions due to its strong directing ability. In this study, the facile and mild Boc protection of the corresponding 8-AQ amide was critical to activate the amide C(acyl)–N bond by twisting its geometry to lower the amidic resonance energy. Both aryl and alkyl amines proceeded transamidation in one-pot, user-friendly conditions with excellent yields.
An efficient nickel-catalyzed removal of alkene protection group under mild condition with high functional group tolerance through chain walking process has been established. Not only phenolic ethers, but also alcoholic ethers can be tolerated with the retention of stereocenter adjacent to hydroxyl group. The new reaction brings the homoallyl group into a start of new type of protecting group.