Modular Synthesis of Chiral N-Protected β-Seleno Amines and Amides via Cleavage of 2-Oxazolidinones and Application in Palladium-Catalyzed Asymmetric Allylic Alkylation
A set of chiral β-seleno amines have been efficiently synthesized via the ring-opening reaction of chiral N-acyl oxazolidin-ones by selenium nucleophiles. These compounds could be transformed into β-seleno amides by reaction with acid chlorides. The present method is applicable to the synthesis of β-chalcogeno amides containing selenium, sulfur and tellurium atoms in good yields. Additionally, these
硒亲核试剂通过手性N-酰基恶唑烷酮的开环反应有效合成了一组手性β-硒胺。这些化合物可以通过与酰氯反应转化为β-硒代酰胺。本方法适用于以良好收率合成含硒、硫和碲原子的β-硫族酰胺。此外,这些新化合物在钯催化的不对称烯丙基烷基化反应中作为配体进行了评估,得到了高达 98% ee 的相应烷基化产物。
One-Pot Indium Iodide Mediated Synthesis of Chiral β-Seleno Amides and Selenocysteine Derivatives by Ring-Opening Reaction of 2-Oxazolines
作者:Antonio L. Braga、Fabrício Vargas、Fábio Z. Galetto、Márcio W. Paixão、Ricardo S. Schwab、Paulo S. Taube
Modular chiral β-selenium-, sulfur-, and tellurium amides: synthesis and application in the palladium-catalyzed asymmetric allylic alkylation
作者:Fabrício Vargas、Jasquer A. Sehnem、Fabio Z. Galetto、Antonio L. Braga
DOI:10.1016/j.tet.2007.10.086
日期:2008.1
have been efficiently synthesized from inexpensive and easily available 2-oxazolines. All the selenium, sulfur, and tellurium compounds were evaluated as chiral ligands in the palladium-catalyzedasymmetricallylicalkylation. The corresponding alkylated products were obtained in excellent enantiomeric excess, using BSA/CH2Cl2 as the base/solvent system.
One-pot modular synthesis of β-chalcogen amides via regioselective 2-oxazolines ring-opening reaction promoted by indium chalcogenolates under microwave irradiation
作者:Larissa F. Guimarães、Luana Bettanin、Roberth N. da Trindade、Cleiton da Silva、Andrielli Leitemberger、Marcelo Godoi、Fábio Z. Galetto
DOI:10.1016/j.tetlet.2020.152180
日期:2020.8
describe herein a microwave-assisted synthesis of β-chalcogen amides through the regioselective ring-opening reaction of 2-oxazolines promoted by bis(organoylchalcogeno)iodo indium(III) in situ generated. This protocol allows the preparation of structurally diverse β-chalcogen amides, with moderate to good yields, within a much shorter reaction time compared to conventional heating protocols.