Selective synthesis of trisubstituted pyrroles through the reactions of alkynyl Fischer carbene complexes with oxazolones
作者:Julio López、Iván Velazco-Cabral、Eloy Rodríguez-deLeón、Clarisa Villegas Gómez、Francisco Delgado、Joaquín Tamariz、Ana Arrieta、Fernando P. Cossío、Miguel A. Vázquez
DOI:10.1039/c9ob02411e
日期:——
An efficient and simple synthesis of novel trisubstituted 1H-pyrroles 4a-qvia 1,3-dipolar cycloaddition of Δ3-trifluoromethyloxazolones 2a-d with both chromium and tungsten alkynyl Fischercarbenecomplexes (1a-h) is described. An unexpected and unreported -CF3 group elimination process was observed in the pyrrole structure. Our experimental and theoretical data suggested that the metal fragment may
Reaktionen von α‐Aminosäuren mit Trifluoressigsäureanhydrid, I. 4
<sup>1</sup>
‐Substituierte 2‐Trifluormethyl‐4‐trifluoracetylmethylen‐oxazolidone‐(5) und Umwandlungsprodukte
作者:Wolfgang Steglich、Volkhard Austel
DOI:10.1002/cber.19671000222
日期:1967.2
Bei der Reaktion vonα-Aminosäurenmit Trifluoressigsäureanhydrid entstehen durch Trifluoressigsäureanhydrid entstehen durch Trifluoracetylierung der primär gebildeten 2-Trifluormethyl-pseudooxazolone-(5) am α-C-Atom der Seitenkette 41-substituierte 2-Trifluormethyl-4-trifluoracetylmethylen-oxazolidone-(5) (2,8,9) sowie deren Enol-trifluoracetate (3,6). Ihre Strukturen werden an Hand der spektro-skopischen
孛DER Reaktion冯α-AminosäurenMITTrifluoressigsäureanhydridentstehen第三人以Trifluoressigsäureanhydridentstehen第三人以Trifluoracetylierung DER PRIMAR gebildeten 2-三氟甲基- pseudooxazolone-(5)点α-C原子DER Seitenkette 4 1 -substituierte 2-三氟甲基-4- trifluoracetylmethylen-oxazolidone-( 5)(2,8,9)大豆烯醇三氟乙酸酯(3,6)。我的工作是由专业人士完成的。因环境而异,因人而异,因人为O-和C- Trifluoracetylierung eines Enaminoketons eintritt。
<i>Cinchona</i> Alkaloid Catalyzed Sulfa-Michael Addition Reactions Leading to Enantiopure β-Functionalized Cysteines
作者:Arjen C. Breman、Suze E. M. Telderman、Roy P. M. van Santen、Jamie I. Scott、Jan H. van Maarseveen、Steen Ingemann、Henk Hiemstra
DOI:10.1021/acs.joc.5b01660
日期:2015.11.6
Sulfa-Michael additions to α,β-unsaturated N-acylated oxazolidin-2-ones and related α,β-unsaturated α-amino acid derivatives have been enantioselectivelycatalyzed by Cinchonaalkaloids functionalized with a hydrogen bond donating group at the C6′ position. The series of Cinchonaalkaloids includes known C6′ (thio)urea and sulfonamide derivatives and several novel species with a benzimidazole, squaramide
The cyclocondensation of trifluoromethyloxazolones with electron-deficient alkenes in the presence of base gives 2-trifluoromethylpyrroles and related heterocyclic compounds in good yields; the reaction involves the tandem Michael addition of trifluoromethyloxazotes to electron-deficient alkenes, intramolecular cyclization and decarboxylation.
Enantioselective Organocatalytic Thiol Addition to α,β-Unsaturated α-Amino Acid Derivatives
作者:Henk Hiemstra、Arjen Breman、Jan Smits、Rene de Gelder、Jan van Maarseveen、Steen Ingemann
DOI:10.1055/s-0032-1317081
日期:——
A new class of Michael acceptors based on α,β-unsaturated amino acids has been prepared and applied in asymmetric organocatalysis. With the use of thiourea derivatives of cinchona alkaloid-derived catalysts, efficient addition of thiols to the dehydroamino acids occurred with formation of β-thiol functionalized α-amino acids in high yields, moderate diastereoselectivities and ee values up to 95%
一类基于α,β-不饱和氨基酸的新型迈克尔受体已被制备并应用于不对称有机催化。使用金鸡纳生物碱衍生催化剂的硫脲衍生物,硫醇有效加成到脱氢氨基酸中,以高产率、中等非对映选择性和高达 95% 的 ee 值形成 β-硫醇官能化的 α-氨基酸。