Amide, peptide, and ester formation DCC is a dehydrating agent for the preparation of
amides,
ketones, and
nitriles. In protein synthesis (such as
Fmoc solid-state synthesizers), the
N-terminus is often used as the attachment site on which the amino acid
monomers are added. To enhance the
electrophilicity of
carboxylate group, the negatively charged oxygen must first be "activated" into a better
leaving group. DCC is used for this purpose. The negatively charged oxygen will act as a
nucleophile, attacking the central carbon in DCC. DCC is temporarily attached to the former carboxylate group forming a highly electrophilic intermediate, making
nucleophilic attack by the terminal amino group on the growing peptide more efficient.
Moffatt oxidation In combination with
dimethyl sulfoxide (DMSO), DCC affects the
Pfitzner–Moffatt oxidation. This procedure is used for the oxidation of
alcohols to
aldehydes and ketones. Unlike metal-mediated
oxidations, such as the
Jones oxidation, the reaction conditions are sufficiently mild to avoid over-oxidation of aldehydes to carboxylic acids. Generally, three equivalents of DCC and 0.5 equivalents of proton source in DMSO are allowed to react overnight at room temperature. The reaction is quenched with acid.
Other reactions • Reaction of an acid with hydrogen peroxide in presence of DCC leads to formation of peroxide linkage. • Alcohols can also be dehydrated using DCC. This reaction proceeds by first giving the
O-acylurea intermediate which is then hydrogenolyzed to produce the corresponding alkene: :RCHOHCH2R′ + (C6H11N)2C → RCH=CHR′ + (C6H11NH)2CO • Secondary alcohols can be stereochemically inverted by formation of a formyl ester followed by
saponification. The secondary alcohol is mixed directly with DCC,
formic acid, and a strong base such as
sodium methoxide. • In the presence of
DMAP, DCC self-condenses two molecules of
phenylacetic acid and its substituted derivatives to produce a
bisbenzyl ketone. ==Biological action==