91603-21-3Relevant articles and documents
Highly Regioselective 5-endo-tet Cyclization of 3,4-Epoxy Amines into 3-Hydroxypyrrolidines Catalyzed by La(OTf)3
Hoshino, Yoshihiko,Iwabuchi, Yoshiharu,Kuriyama, Yuse,Sasano, Yusuke,Uesugi, Shun-ichiro,Yamaichi, Aoto
supporting information, p. 1961 - 1965 (2021/01/04)
Highly regioselective intramolecular aminolysis of 3,4-epoxy amines has been achieved. Key features of this reaction are (1) chemoselective activation of epoxides in the presence of unprotected aliphatic amines in the same molecules by a La(OTf)3 catalyst and (2) excellent regioselectivity for anti-Baldwin 5-endo-tet cyclization. This reaction affords 3-hydroxy-2-alkylpyrrolidines stereospecifically in high yields. DFT calculations revealed that the regioselectivity might be attributed to distortion energies of epoxy amine substrates. The use of this reaction was demonstrated by the first enantioselective synthesis of an antispasmodic agent prifinium bromide.
Asymmetric Total Synthesis of 19,20-Epoxydocosapentaenoic Acid, a Bioactive Metabolite of Docosahexaenoic Acid
Cinelli, Maris A.,Lee, Kin Sing Stephen
, p. 15362 - 15372 (2019/11/28)
In this study, we report the first asymmetric total synthesis of 19,20-epoxydocosapentaenoic acid (19,20-EDP), a naturally occurring bioactive cytochrome P450 metabolite of docosahexaenoic acid, a major constituent of fish oil. Our strategy involves direct asymmetric epoxidation to produce an enantiopure β-epoxyaldehyde that can be appended to the rest of the skipped polyene core by Wittig condensation. Our route is step-economical and late divergent and could be an appealing method by which to synthesize EDP analogues for biological studies.
Catalytic activity of molybdenum(II) complexes in homogeneous and heterogeneous conditions
Vasconcellos Dias, Maria,Saraiva, Marta S.,Ferreira, Paula,Calhorda, Maria José
, p. 1465 - 1478 (2015/05/13)
The new complexes [MoBr(η3-C3H5)(CO)2(L)2] (C1) and [MX2(CO)3(L)2] (M = Mo(II), X = I (C2); M = Mo(II), X = Br (C3); M = W(II), X = I (C4); M = W(II), X = Br (C5)) were synthesized by reaction of 2-amino-1,3,4-thiadiazole (L) with [MoBr(η3-C3H5)(CO)2(NCCH3)2] (1), [MoI2(CO)3(CH3CN)2](M = Mo (2); M = W (4)), or [MoBr2(CO)3(CH3CN)2](M = Mo (3); M = W (5)) in 2:1 ratio. The five complexes were immobilized in MCM-41, yielding the materials MCM-Cn (n = 1-5), and C1 was also immobilized in silica gel (Silica-C1) and in a polyhedral oligomeric silsesquioxane (Cube-C1). Complexes and materials were fully characterized by spectroscopic techniques and elemental analysis. DFT calculations showed that several C1 isomers should coexist. The as synthesized and supported complexes were tested as catalysts on the oxidation of geraniol, cis-hex-3-en-1-ol, trans-hex-3-en-1-ol, (S)-limonene, and 1-octene. The conversions and TOF significantly depend on the complex and the nature of the substrate. The general conclusions are (i) complex C1 has the highest activity; (ii) tungsten complexes C4 and C5 are more active than the molybdenum analogues; (iii) the immobilization of the catalysts improves the performance; and (iv) silica gel and the polyhedral oligomeric silsesquioxane supports modify the selectivity, leading to products different from the one obtained with MCM for specific substrates.
