[EN] ASYMMETRIC ELECTROPHILIC FLUORINATION USING AN ANIONIC CHIRAL PHASE-TRANSFER CATALYST<br/>[FR] FLUORATION ÉLECTROPHILE ASYMÉTRIQUE UTILISANT UN CATALYSEUR DE TRANSFERT DE PHASE CHIRAL ANIONIQUE
申请人:UNIV CALIFORNIA
公开号:WO2013096971A1
公开(公告)日:2013-06-27
The discovery of distinct modes of asymmetric catalysis has the potential to rapidly advance chemists' ability to build enantioenriched molecules. As an example, the use of chiral cation salts as phase-transfer catalysts for anionic reagents has enabled a vast set of enantioselective transformations. A largely overlooked analogous mechanism wherein a chiral anionic catalyst brings a cationic species into solution is itself a powerful method. The concept is broadly applicable to a number of different reaction pathways, including to the enantioselective fluorocyclization of olefins, and dearomatization of aromatic systems with a cationic electrophile-transferring (e.g., fluorinating) agent and a chiral phosphate catalyst. The reactions proceed in high yield and stereoselectivity. The compounds and methods of the invention are of particular value, especially considering the scarcity of alternative approaches.
Electrochemical oxidative radical cascade cyclization of olefinic amides and thiophenols towards the synthesis of sulfurated benzoxazines, oxazolines and iminoisobenzofurans
containing N and O are important structures in pharmaceuticals, agrochemicals and functional molecules. The synthesis of these compounds usually requires complex substrates and harsh reaction conditions. Herein, we introduce a mild and efficient electrochemical oxidative strategy to construct benzoxazines, oxazolines and iminoisobenzofurans without the requirement of a transition-metal catalyst and an
含 N 和 O 的杂环是药物、农用化学品和功能分子中的重要结构。这些化合物的合成通常需要复杂的底物和苛刻的反应条件。在此,我们引入了一种温和有效的电化学氧化策略来构建苯并恶嗪、恶唑啉和亚氨基异苯并呋喃,而无需过渡金属催化剂和外部氧化剂。在一个简单的未分开的细胞中,各种烯酰胺和苯硫酚/二硒化物反应生成 69 个硫醇化和硒化杂环的例子,产率高达 83%。此外,这种自由基级联反应为一步构建 C-S/C-Se 和 C-O 键提供了一种简便的方法。
Copper-catalyzed trifluoromethylation of alkenes: synthesis of trifluoromethylated benzoxazines
base and ligand free copper catalyzed method for the construction of trifluoromethylated benzoxazines has been developed by using Umemoto's reagent. It involves the oxidative difunctionalization of alkenes through tandem C–O and C–CF3 bond formations. Furthermore, synthesized benzoxazines were selectively converted into trifluoromethylated allylic and (E)-vinylic benzamides by the treatment of KOtBu
通过使用梅本试剂开发了一种简单的无碱和无配体铜催化的三氟甲基化苯并恶嗪的构建方法。它涉及通过串联的C–O和C–CF 3键形成烯烃的氧化双官能团。此外,通过分别处理KO t Bu和CH 3 Li,将合成的苯并恶嗪选择性地转化为三氟甲基化的烯丙基和(E)-乙烯基苯甲酰胺。
Organocatalytic Synthesis of Oxazolines and Dihydrooxazines from Allyl-Amides: Bypassing the Inherent Regioselectivity of the Cyclization
作者:Alexis Theodorou、Ierasia Triandafillidi、Christoforos G. Kokotos
DOI:10.1002/adsc.201701386
日期:2018.3.1
construction of either oxazolines or dihydrooxazines from the corresponding allyl‐amides is reported. Bypassing the inherent selectivity of the cyclization and depending on the substitution pattern of the substrate, a selective epoxidation‐cyclization was developed leading to either the five‐membered or the six‐membered ring, upon simple and complementary reaction conditions. The cyclization products were obtained
Regioselective synthesis of benzazetines and indoles from o-alkenylanilides was achieved. The reaction of o-vinylbenzanilide with dimethyl(methylthio)sulfonium trifluoromethanesulfonate (DMTST) gave the corresponding benzazetine in 92% yield, whereas the reaction of o-vinyl-N-p-toluenesulfonylanilide gave N-tosylindoline in 77% yield. 3-Methy-N-p-tosylindole was directly synthesized by the reaction of o-isopropenyl-N-p-tosylanilide with dimethyl disulfide and methyl triflate in 85% yield.