Adding a keto group to an aromatic or aliphatic substrate using an acyl halide or anhydride in the presence of a Lewis acid catalyst is called the Friedel-Crafts acylation. The reactive electrophile in this aromatic substitution is either an acylium ion or an acyl chloride-Lewis acid complex. [1] Benzene and...

The Baeyer-Villiger oxidation reaction uses an oxidizing agent such as peroxyacid to convert ketones or cyclic ketones to esters and lactones/ hydroxy acid respectively. Peroxyacid first attacks a protonated carbonyl group, forming a tetrahedral intermediate named the Criegee intermediate. An alkyl migration and loss of carboxylic acid then takes place...

The Fischer indole synthesis uses a protic or Lewis acid catalyst to convert a phenylhydrazine and an aldehyde or ketone to an indole. The phenylhydrazine makes an iminium ion with the carbonyl compound, which tautomerizes to the ene-hydrazine. A [3,3]-sigmatropic rearrangement disrupts the aromatic ring, but a subsequent proton transfer...

The Fischer esterification uses a catalytic acid to convert a carboxylic acid and alcohol to an ester. Protonation of the carbonyl oxygen activates the carboxylic acid to nucleophilic attack by the alcohol, producing a tetrahedral intermediate with two hydroxyl groups. Ester formation occurs when a proton is transferred to one...

The Beckmann rearrangement involves the use of a strong acid to rearrange an oxime (aldoxime or ketoxime) to an amide. First the oxime hydroxyl group receives a proton from the acid, forming a leaving group. A [1,2]-shift of the R group, which is anti to the leaving group, then promotes...

The Buchwald-Hartwig cross-coupling reaction (Buchwald-Hartwig Amination) uses catalytic palladium and a strong base in stoichiometric amounts to make an aryl amine from an aryl halide and a 1° or 2° amine. Oxidative addition of the aryl halide to the Pd(0) catalyst occurs first, followed by amine coordination to the Pd(II)...