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Nitrile hydratase and amidase are two hydrating and hydrolytic enzymes responsible for the sequential metabolism of nitriles in bacteria that are capable of utilising nitriles as their sole source of nitrogen and carbon, and in concert act as an alternative to nitrilase activity, which performs nitrile hydrolysis without formation of an intermediate primary amide.
Nitrilase enzymes (nitrile aminohydrolase; EC 3.5.5.1) catalyse the hydrolysis of nitriles to carboxylic acids and ammonia, without the formation of "free" amide intermediates. [1] Nitrilases are involved in natural product biosynthesis and post translational modifications in plants, animals, fungi and certain prokaryotes.
The classical procedure to convert a nitrile to the corresponding primary amide calls for adding the nitrile to cold concentrated sulfuric acid. [29] The further conversion to the carboxylic acid is disfavored by the low temperature and low concentration of water. RC≡N + H 2 O → RC(O)NH 2. Two families of enzymes catalyze the hydrolysis of ...
The resulting nitrilium ion is hydrolyzed to the desired amide. Primary, [7] secondary, [4] tertiary, [8] and benzylic [9] alcohols, [1] as well as tert-butyl acetate, [10] also successfully react with nitriles in the presence of strong acids to form amides via the Ritter reaction. A wide range of nitriles can be used.
The mechanism for the reduction of a nitrile to an aldehyde with DIBAL-H. The hydride reagent Diisobutylaluminium hydride, or DIBAL-H, is commonly used to convert nitriles to the aldehyde. [14] Regarding the proposed mechanism, DIBAL forms a Lewis acid-base adduct with the nitrile by formation of an N-Al bond. The hydride is then transferred to ...
With nitrile electrophiles, nucleophilic addition take place by: [1] hydrolysis of a nitrile to form an amide or a carboxylic acid; organozinc nucleophiles in the Blaise reaction; alcohols in the Pinner reaction. the (same) nitrile α-carbon in the Thorpe reaction. The intramolecular version is called the Thorpe–Ziegler reaction.
Hydrolysis of 5 produces a hemiaminal (6) from which an aldehyde (7) is formed. Substitutes that increase the electron density promote the formation of the aldimine-tin chloride adduct. With electron withdrawing substituents, the formation of an amide chloride is facilitated. [4]
The core −C(=O)−(N) of amides is called the amide group (specifically, carboxamide group). In the usual nomenclature, one adds the term "amide" to the stem of the parent acid's name. For instance, the amide derived from acetic acid is named acetamide (CH 3 CONH 2 ).