Cooperative Covalent–Noncovalent Organocatalysis of the Knoevenagel Condensation Based on an Amine and Iodonium Salt Mixture
Alexandra A. Sysoeva, Mikhail V. Il’in, Dmitrii S. Bolotin
Abstract
Abstract The experimentally obtained kinetic data has indicated the existence of a synergetic cocatalytic effect provided by an iodonium salt in the base‐catalyzed Knoevenagel condensation. The diphenyliodonium triflate serving as the halogen bond‐donating Lewis acid provides the higher cocatalytic effect than zinc(II) triflate or triflic acid serving, respectively, as the metal cation‐based Lewis acid and Brønsted acid. Such a cocatalytic effect remains the same for a broad scope of carbonyl compounds covering aldehydes featuring electron‐withdrawing or electron‐donating substituents, as well as ketone involved in the reaction.
Topics & Concepts
Knoevenagel condensationChemistryTrifluoromethanesulfonateLewis acids and basesOrganocatalysisKetoneCatalysisSalt (chemistry)Organic chemistryPolymer chemistryMedicinal chemistryEnantioselective synthesisOxidative Organic Chemistry ReactionsAsymmetric Synthesis and CatalysisSynthetic Organic Chemistry Methods