Metal-free halogen, chalcogen, or oxocarbenium ion mediated yne-carbonyl or yne-thioxo transformations of a range of N-and O-propargylic compounds have been studied. This investigation has led to the development of a mild, economic, and effective method for the synthesis of functionalized 4H-

A scalable synthesis of chiral Vedejs-type DMAP catalysts is reported. The key step of the synthesis is amination of the enantiomerically pure 4-chloropyridine derivative using well-defined ZnCl 2 (amine) 2 complexes. A series of Zn(II)−amine complexes have been synthesized to explore the scope of the ZnCl 2 -mediated amination of 4-halopyridines. Mechanistic studies support a Zn(II)-facilitated nucleophilic aromatic substitution as a plausible mechanism for the chlorine-to-amine exchange.

Non-enzymatic dynamic kinetic resolution (DKR) of secondary alcohols by enantioselective acylation using an isothiourea-derived HyperBTM catalyst and racemization of slowly reacting alcohol by Bäckvall’s ruthenium complex is reported. The DKR approach features high enantioselectivities (up to 99:1), employs easy-to-handle crystalline 4-nitrophenyl isobutyrate as the acylating reagent, and proceeds at room temperature and under an ambient atmosphere. The stereoinduction model featuring cation−π system interactions between the acylated HyperBTM catalyst and π electrons of an alcohol aryl subunit has been elaborated by DFT calculations.