Amino acids (glycine, β-alanine, γ-aminobutyric and ε-aminocapronic acids, d,l-valine, and d,l-leucine) react under biomimetic conditions (H2O, NaOH, pH Ë8.6-9.9, room temperature) smoothly with α,β-acetylenic γ-hydroxyacid nitriles to give a novel family of unnatural amino acids containing a 5-imino-2,5-dihydro-3-furanyl substituent at the amino group, in 61-98% yield. As follows from a single-crystal X-ray analysis of 2-[(5-imino-2,2-dimethyl-2,5-dihydro-3-furanyl)amino]acetic acid, the synthesized amino acids are zwitterions with a protonated imino group in the iminodihydrofuran moiety.
Expedient synthesis of pyrazoles substituted with amino, hydroxyl and thioamide groups
作者:Boris A. Trofimov、Anastasiya G. Mal’kina、Angela P. Borisova、Valentina V. Nosyreva、Olesya A. Shemyakina、Olga N. Kazheva、Gennadii V. Shilov、Oleg A. Dyachenko
DOI:10.1016/j.tetlet.2008.03.046
日期:2008.5
The reaction of α,β-acetylenic γ-hydroxy nitriles with thiosemicarbazide, under mild conditions (rt, no catalyst, in 1:1 aqueous ethanol, 4–14 h), proceeds chemo-, regio- and stereoselectively to give atypically so far inaccessible tri-functionalized (amino, hydroxyl and thioamide groups) pyrazoles in 53–91% yields. The hydroxyl function is easily protected by using the corresponding acetals of the
Chemo-, regio- and stereospecific non-catalytic addition of isonicotinic acid to, -acetylenic -hydroxy nitriles
作者:Boris A. Trofimov、Anastasiya G. Mal’kina、Olesya A. Shemyakina、Valentina V. Nosyreva、Angela P. Borisova、Olga N. Kazheva、Grigorii G. Alexandrov、Oleg A. Dyachenko
DOI:10.1016/j.mencom.2008.09.018
日期:2008.9
Isonicotinic acid is readily added to α,β-acetylenic γ-hydroxy nitriles through its nitrogen atom under mild non-catalytic conditions in water (50–55 °C, 45–50 h) to afford chemo-, regio- and stereospecifically 1-[(Z)-2-cyano-1-(1-hydroxy-1-alkylethyl)ethenyl]-pyridinium-4-carboxylates, densely functionalized derivatives of isonicotinic acid (45–90% yields). The structure and zwitterionic character
Chemo- and regioselective modification of D,L-phenylalanine with α-cyanoacetylenic alcohols in water
作者:Anastasiya G. Mal’kina、Angela P. Borisova、Valentina V. Nosyreva、Olesya A. Shemyakina、Alexander I. Albanov、Boris A. Trofimov
DOI:10.3998/ark.5550190.0012.921
日期:——
D,L-Phenylalanine reacts with -cyanoacetylenic alcohols under biomimetic conditions (room temperature, water) to give a novel family of unnatural amino acids, containing 2,5-dihydro-5iminofuranyl substituents in the amino group, in almost quantitative yields (92-95%). This “green” one-pot version of the tandem assembly of nontraditional amino acids opens an unexplored avenue to the new types of drugs