Inchemistry,acylation is a broad class ofchemical reactions in which anacyl group (R−C=O) is added to a substrate. The compound providing the acyl group is called theacylating agent. The substrate to be acylated and the product include the following:
A particularly common type of acylation isacetylation, the addition of the acetyl group. Closely related to acylation isformylation, which employ sources of "HCO+ in place of "RCO+".
Because they form a strongelectrophile when treated withLewis acids,acyl halides are commonly used as acylating agents. For example,Friedel–Crafts acylation usesacetyl chloride (CH3COCl) as the agent andaluminum chloride (AlCl3) as a catalyst to add anacetyl group tobenzene:[2]
This reaction is an example ofelectrophilic aromatic substitution.
Acyl halides andacid anhydrides ofcarboxylic acids are also common acylating agents. In some cases,active esters exhibit comparable reactivity. All react withamines to formamides and withalcohols to formesters bynucleophilic acyl substitution.
Acylation can be used to preventrearrangement reactions that would normally occur inalkylation. To do this an acylation reaction is performed, then the carbonyl is removed byClemmensen reduction or a similar process.[3]
Protein acylation is thepost-translational modification ofproteins via the attachment offunctional groups through acyl linkages. Protein acylation has been observed as a mechanism controlling biological signaling.[4] One prominent type is fatty acylation, the addition offatty acids to particularamino acids (e.g.myristoylation,palmitoylation orpalmitoleoylation).[5] Different types of fatty acids engage in global protein acylation.[6] Palmitoleoylation is an acylation type where themonounsaturated fatty acidpalmitoleic acid iscovalently attached toserine orthreonineresidues of proteins.[7][8] Palmitoleoylation appears to play a significant role in the trafficking, targeting, and function ofWnt proteins.[9][10]
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