acyltransfer

Acyltransfer refers to a broad set of chemical reactions in which an acyl group, typically a carbonyl-containing moiety such as R-CO-, is transferred from a donor molecule to an acceptor. The reaction is usually described as a nucleophilic acyl substitution: a nucleophile attacks the carbonyl carbon of the acyl donor, forming a tetrahedral intermediate, and a leaving group is expelled, resulting in the transfer of the acyl group to the acceptor. The donor is often an acyl derivative such as an acyl chloride, an acid anhydride, an ester, or a thioester, while the acceptor is a nucleophile such as an alcohol, an amine, thiol, or water. The efficiency and selectivity depend on leaving-group ability, competing reactions, and catalysts.

In organic synthesis, acyl transfer reactions are used to form esters and amides, transfer acyl groups between derivatives (transacylation), and in transesterification processes that redistribute ester groups. In biochemistry, acyltransferases are enzymes that catalyze the transfer of acyl groups from acyl-CoA donors to acceptors including proteins, sugars, or lipids. These enzymes drive lipid biosynthesis, detoxification, and protein modification. Common biological examples include acetyltransferases (transferring acetyl groups) and cholesterol acyltransferase (ACAT), which transfers fatty acyl groups to cholesterol.

Overall, acyltransfer encompasses both synthetic and enzymatic processes that enable the construction and modification of esters, amides, lipids, and related structures through transfer of the acyl moiety.