camphorsulfonic

Camphorsulfonic acid (CSA) is an organosulfur compound produced by the sulfonation of camphor. It is an optically active, strongly acidic Brønsted acid that is widely used as a catalyst in enantioselective organic synthesis. CSA is typically employed in its chiral form, with both enantiomers available for various stereochemical applications, and it often functions as a catalyst or resolving agent in reactions that require chiral induction.

Preparation and properties: CSA is prepared by sulfonating camphor with concentrated sulfuric acid or oleum, followed by isolation of the camphorsulfonic acid. The compound is a solid at room temperature and is usually obtained as a crystalline material. It is highly soluble in water and many polar organic solvents and can form salts with bases. The camphor skeleton imparts inherent chirality to CSA, making it useful for asymmetric catalysis and for resolving racemic mixtures.

Uses: The primary role of camphorsulfonic acid is as a chiral Brønsted acid catalyst in enantioselective transformations. It is employed to activate substrates such as carbonyl compounds and imines and can facilitate a variety of reactions, including aldol, Mannich, and cycloaddition processes, in non-aqueous media. Beyond catalysis, CSA can serve as a resolving agent or as part of catalytic systems that exploit its optical activity.

Safety and handling: CSA is a corrosive material that can cause irritation to skin, eyes, and the respiratory tract. It should be handled with appropriate personal protective equipment, in a well-ventilated area, and stored in a cool, dry place away from incompatibles.