- Organocatalytic Decarboxylation of Amino Acids as a Route to Bio-based Amines and Amides
-
Amino acids obtained by fermentation or recovered from protein waste hydrolysates represent an excellent renewable resource for the production of bio-based chemicals. In an attempt to recycle both carbon and nitrogen, we report here on a chemocatalytic, metal-free approach for decarboxylation of amino acids, thereby providing a direct access to primary amines. In the presence of a carbonyl compound the amino acid is temporarily trapped into a Schiff base, from which the elimination of CO2 may proceed more easily. After evaluating different types of aldehydes and ketones on their activity at low catalyst loadings (≤5 mol%), isophorone was identified as powerful organocatalyst under mild conditions. After optimisation many amino acids with a neutral side chain were converted in 28–99 % yield in 2-propanol at 150 °C. When the reaction is performed in DMF, the amine is susceptible to N-formylation. This consecutive reaction is catalysed by the acidity of the amino acid reactant itself. In this way, many amino acids were efficiently transformed to the corresponding formamides in a one-pot catalytic system.
- Claes, Laurens,Janssen, Michiel,De Vos, Dirk E.
-
p. 4297 - 4306
(2019/08/26)
-
- Enantioselective hydrogenation of allylphthalimides: An efficient method for the synthesis of β-methyl chiral amines
-
(Chemical Equation Presented) High yields and up to 98% ee have been achieved by asymmetric hydrogenation of allylphthalimides followed by hydrolysis to give β-methyl chiral amines by using a Ru-C3-tunephos catalyst (see scheme). The synthetic utility of this procedure has been demonstrated through the synthesis of the key intermediate of the LTs receptor antagonist (Zeneca ZD 3532).
- Wang, Chun-Jiang,Sun, Xianfeng,Zhang, Xumu
-
p. 4933 - 4935
(2007/10/03)
-
- Synthesis and odor evaluation of stereoisomers of imine derivatives in roasted spotted shrimp
-
All possible stereoisomers of imine derivatives 1-4. which have the characteristic roast odor of seafood, were synthesized. As a result of odor evaluation of all isomers, we found that each isomer has a different and characteristic odor of roasted seafood.
- Tachihara, Toru,Ishizaki, Susumu,Kurohayashi, Yoshiko,Tamura, Hiroshi,Ikemoto, Youichi,Onuma, Atsushi,Yoshikawa, Keisuke,Yanai, Tetsuya,Kitahara, Takeshi
-
p. 274 - 279
(2007/10/03)
-
- One-pot sequence for the decarboxylation of α-amino acids
-
Treatment of an α-amino acid with N-bromosuccinimide in water at pH 5 or in an alcoholic-aqueous ammonium chloride mixture, followed by addition of nickel(II) chloride and sodium borohydride, effected an overall decarboxylation via an intermediate nitrile to afford the corresponding amine in good yield.
- Laval, Gilles,Golding, Bernard T.
-
p. 542 - 546
(2007/10/03)
-
- CD OF PRIMARY AMINES AND 1- OR 3-SUBSTITUTED TETRAHYDROISOQUINOLINES IN PRESENCE OF
-
The syntheses of (S)-(-)-1,2-dimethyl-1,2,3,4-tetrahydroisoquinoline (IX) and S-(+)-2,3-dimethyl-1,2,3,4-tetrahydroisoquinoline (XVI) in optically pure form and with known absolute configuration is described.The CD and NMR spectra of these compounds and of most of their intermediates are given, and from these data could be deduced, that the N-methyl groups of the two bases IX and XVI adopt different conformations in solution, but the same (viz. axial) in their complexes with .
- Diener, Wolfgang,Frelek, Jadwiga,Snatzke, Guenther
-
p. 954 - 965
(2007/10/02)
-
- PREPARATION OF (S)-2-METHYLBUTYLAMINE AND SYNTHESIS OF CHIRAL ISOLEUCINE AND alloISOLEUCINE.
-
A four-step synthesis (45 percent total yield) of a mixture of chiral pure L-isoleucine and D-alloisoleucine is reported, via a route comprising an anodic oxidation of suitable acylamide precursors.Efficient preparations for (S)-2-methylbutylamine from the cheap parent (S)-alcohol are described.
- Anteunis, M. J. O.,Callens, R.,Witte, M. De,Reyniers, M. F.,Spiessens, L.
-
p. 545 - 554
(2007/10/02)
-