13474-14-1Relevant academic research and scientific papers
One-pot reductive amination of carboxylic acids: a sustainable method for primary amine synthesis
Coeck, Robin,De Vos, Dirk E.
supporting information, p. 5105 - 5114 (2020/08/25)
The reductive amination of carboxylic acids is a very green, efficient and sustainable method for the production of (bio-based) amines. However, with current technology, this reaction requires two to three reaction steps. Here, we report the first (heterogeneous) catalytic system for the one-pot reductive amination of carboxylic acids to amines, with solely H2 and NH3 as the reactants. This reaction can be performed with relatively cheap ruthenium-tungsten bimetallic catalysts in the green and benign solvent cyclopentyl methyl ether (CPME). Selectivities of up to 99% for the primary amine could be achieved at high conversions. Additionally, the catalyst is recyclable and tolerant for common impurities such as water and cations (e.g. sodium carboxylate).
Carbohydrates as efficient catalysts for the hydration of α-amino nitriles
Chitale, Sampada,Derasp, Joshua S.,Hussain, Bashir,Tanveer, Kashif,Beauchemin, André M.
supporting information, p. 13147 - 13150 (2016/11/09)
Directed hydration of α-amino nitriles was achieved under mild conditions using simple carbohydrates as catalysts exploiting temporary intramolecularity. A broadly applicable procedure using both formaldehyde and NaOH as catalysts efficiently hydrated a variety of primary and secondary susbtrates, and allowed the hydration of enantiopure substrates to proceed without racemization. This work also provides a rare comparison of the catalytic activity of carbohydrates, and shows that the simple aldehydes at the basis of chemical evolution are efficient organocatalysts mimicking the function of hydratase enzymes. Optimal catalytic efficiency was observed with destabilized aldehydes, and with difficult substrates only simple carbohydrates such as formaldehyde and glycolaldehyde proved reliable.
Dynamic kinetic resolution of α-aminonitriles to form chiral α-amino acids
Yasukawa, Kazuyuki,Hasemi, Ryuji,Asano, Yasuhisa
supporting information; scheme or table, p. 2328 - 2332 (2011/10/19)
We have succeeded in the enzymatic synthesis of (R)-α-aminobutyric acid from racemic α-aminobutyronitrile. This has been demonstrated by the use of non-stereoselective nitrile hydratase (NHase) from Rhodococcus opacus 71D, D-aminopeptidase from Ochrobactrum anthropi C1-38 and α-amino-ε- caprolactam (ACL) racemase from Achromobacter obae. Racemic α- aminobutyronitrile was completely converted in 6 h at 30 °C to (R)-α-aminobutyric acid whose optical purity was more than 99%. (S)-α-Aminobutyric acid was also synthesized from α- aminobutyronitrile by NHase, ACL racemase and L-amino acid amidase from Brevundimonas diminuta TPU 5720. In a similar manner, other (R)- or (S)-α-amino acids with more than 97.5% ee could be synthesized from the corresponding α-aminonitriles. This is the first report on the dynamic kinetic resolution (DKR) of α-aminonitriles to form chiral α-amino acids. The key enzyme in this DKR is non-stereoselective NHase, which had been newly screened from soil samples, and its gene cloned. Copyright
Substituent effect on acidity of substituted 2-(4-nitrobenzoylamino)alkanamidesin methanol-dimethyl sulfoxide mixtures
Mitas, Petr,Sedlak, Milos,Kavalek, Jaromir
, p. 85 - 93 (2007/10/03)
The dissociation constants of substituted 2-(4-nitrobenzoylamino)alkanamides, N-[2-(4-nitrobenzoylamino)aikanoyl]pyrrolidines, and N-alkyl-4-nitrobenzamides have been measured spectrophotometrically in 60 and 80% v/v DMSO. The pKA values of these N-acids are discussed from the point of view of substituents at the acetamide a-carbon atom.
α-Aminonitrile hydration in the presence of hydrogen peroxide in aqueous basic medium
Taillades, Jacques
, p. 89 - 100 (2007/10/03)
α-Aminonitriles are hydrated into α-aminoamides in the presence of hydrogen peroxide in sodic or ammoniacal basic medium. While the hydration mechanism is close to the mechanism described previously in the case of aromatic nitrites, we showed that, in weakly basic conditions, the amine function of α-aminonitrile is competitively oxidized via a peroxyimidic acid by an intramolecular process. In the case of 2-aminopropanenitrile, this reaction leads to pyruvamide oxime. Furthermore, the study of structurereactivity relationships in the hydration of aliphatic and aromatic monofunctional nitriles and α-aminonitriles showed that the reactivity of the substrates towards hydroperoxide onion, which mostly depends on inductive effects of the substituents, is sufficiently enhanced to allow hydration of tertiary α-aminonitriles with low steric hindrance and regioselective hydration of dissymmetric α-aminodinitriles. Eisevier,.
Auxiliary chiral ketones in the asymmetric synthesis of α-amino acids by Strecker reaction
Bousquet, C.,Tadros, Z.,Tonnel, J.,Mion, J.,Taillades, J.
, p. 513 - 520 (2007/10/02)
The asymmetric synthesis of α-aminoamides 1 R1CH(CONH2)NH2 1 = Ph-CH2, 1b: R1 = Pri, 1c: R1 = Ph> that leads to the corresponding α-amino acids is achieved by a classical Strecker reaction 1CHO, HCN, NH3> using an auxiliary chiral ketone (R2R'2CO) as a catalyst.In the presence of an aqueous solution of HCN and NH3, the (-)-5R-(methylethenyl)-3R-cyano-2R-methylcyclohexanone 2(-) leads to the 5R-(methylethenyl)-3R-cyano-2R-methyl-1R-cyano-cyclohexylamine 3 with 80percent stereoselectivity.Following condensation with R1CHO, this α-aminonitrile R2R'2C(CN)NH2 3 yields the corresponding iminonitrile which undergoes a second asymmetric addition of HCN yielding an asymmetric α-aminodinitrile 4 R2R'2C(CN)-NH-CHR1(CN) with stereoselectivity that varies betweeen 62percent (R1 = Ph) and 79percent (R1 = Ph-CH2).The α-aminodinitrile obtained as the major product undergoes regioselective hydration of the secondary aminonitrile moiety followed by the decomposition ("retro-Strecker") of the tertiary aminonitrile moiety yielding an optically active α-aminoamide (eg 78percent optical purity for 1a) and the auxiliary chiral ketone 2 and ketonic derivatives.Keywords - α-aminonitrile / α-amino acid / asymmetric synthesis
Process for the preparation of alpha-amino alpha-hydrogen carboxylic acid amides
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, (2008/06/13)
The invention relates to a process for the preparation of α-amino-α-hydrogen carboxylic acid amides of the formula where R1 represents alkyl, alkaryl, aryl, alkenyl, heteroalkyl or heteroaryl, whether or not substituted, by conversion of the corresponding amino nitriles and is characterized in that the conver-sion takes place in the presence of hydrogen peroxide and ammonia. By preference use is made of 2-6 moles hydrogen peroxide and 3-12 moles ammonia per mole α-amino nitrile.
Analgesic polypeptide
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, (2008/06/13)
The polypeptides of the formula: STR1 in which R is hydrogen, methyl, allyl or cyclopropylmethyl; and R2 is --OH, --NH2 or --NHCn H2n+1 where N is 1,2,3 or 4 Or a pharmaceutically acceptable salt thereof, exert an analgesic effect in warm-blooded animals when peripherally administered.
