Acylation is a chemical reaction that involves the introduction of an acyl group into a molecule. An acyl group is derived from a carboxylic acid by removing the hydroxyl (-OH) part, resulting in a structure that typically contains a carbonyl group (C=O) bonded to a carbon atom. This process is commonly used in organic chemistry to modify compounds, enhancing their reactivity or changing their properties. In many cases, acylation is performed using acyl chlorides or anhydrides, which react with nucleophiles like alcohols or amines. This reaction is important in the synthesis of various organic compounds, including pharmaceuticals and polymers, and is a key step in the formation of esters and amides.