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2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (or DDQ) is the chemical reagent with formula C 6 Cl 2 (CN) 2 O 2. This oxidant is useful for the dehydrogenation of alcohols, [3] phenols, [4] and steroid ketones. [5] DDQ decomposes in water, but is stable in aqueous mineral acid. [6]
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is often the reagent of choice. DDQ and an acid catalyst has been used to synthesise a steroid with a phenanthrene core by oxidation accompanied by a double methyl migration. [9] In the process, DDQ is itself reduced into an aromatic hydroquinone product.
Benzyl ethers: Benzyl (Bn) — Removed by hydrogenolysis. [19] Bn group is widely used in sugar and nucleoside chemistry. Trityl (triphenylmethyl, Tr) — Removed by acid [20] [21] [22] and hydrogenolysis; p-Methoxybenzyl ether (PMB) — Removed by acid, hydrogenolysis, or oxidation – commonly with DDQ. [23]
Through a variety of mechanisms, the removal of a hydride equivalent converts a primary or secondary alcohol to an aldehyde or ketone, respectively. The oxidation of primary alcohols to carboxylic acids normally proceeds via the corresponding aldehyde, which is transformed via an aldehyde hydrate ( gem -diol, R-CH(OH) 2 ) by reaction with water.
The auto-oxidation of the neurotransmitter dopamine and its precursor L-Dopa generates the comparatively stable dopamine quinone which inhibits the functioning of dopamine transporter (DAT) and the TH enzyme and leads to low mitochondrial ATP production. [15] The benzoquinone blattellaquinone is a sex pheromone in cockroaches.
The unsubstituted compound can be prepared by oxidation of 2,2'-dipyrrolemethane with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) at −78 °C in dry dichloromethane solution. [1] An alternative synthesis that avoids the oxidation step is the condensation of 2-formyl pyrrole and pyrrole catalyzed by trifluoroacetic acid , followed by ...
Photocyclization can be used as the final step of a sequence to generate a fused aromatic ring at a benzylic position. After benzylic bromization with N-bromosuccinimide, transformation to the phosphonium salt, and a Wittig reaction with anaromatic aldehyde, photocyclization fuses the aromatic rings. Iteration of this sequence results in helicenes.
Rather, it is formed by oxidation of dimethyl sulfide with an oxidant (NCS). The reaction mechanism of Corey–Kim oxidation. Under Corey–Kim conditions allylic and benzylic alcohols have a tendency to evolve to the corresponding allyl and benzyl chlorides unless the alcohol activation is very quickly followed by addition of triethylamine. In ...