Catalytic Asymmetric Diazoacetate Cyclopropanation of 1-Tosyl-3-vinylindoles. A Route to Conformationally Restricted Homotryptamines
摘要:
Substituted 1-tosyl-3-vinylindoles undergo catalytic asymmetric cyclopropanation with ethyl- and tert-butyldiazoacetate to afford N-protected trans-2-(indol-3-yl)-1-cyclopropanecarboxylic esters in good yield and high enantiomeric excess (81-88% ee). The resulting cycloadducts are demonstrated to be useful intermediates for the synthesis of conformationally restricted, homotryptamine-like analogues such as BMS-505130.
Fe(III)‐Catalyzed, Cyclizative Coupling between 2‐Alkynylbenzoates and Carbinols: Rapid Generation of Polycyclic Isocoumarins and Phthalides and Mechanistic Study
作者:Soniya Gandhi、Beeraiah Baire
DOI:10.1002/adsc.202000313
日期:2020.7.16
catalyzed, highly regioselective cyclizative coupling of internal alkynes with alcohols has been reported for the rapid synthesis of structurally divergent, complex isocoumarins and phthalides respectively in intermolecular and intramolecular fashion. This strategy exhibited very high substrate scope and efficiency and proceeds through the simultaneous formation of C−O and C−C bonds. Observations from
Enantioselective Copper-Catalyzed Fukuyama Indole Synthesis from 2-Vinylphenyl Isocyanides
作者:Till Drennhaus、Dirk Leifert、Jessika Lammert、Jan Philipp Drennhaus、Klaus Bergander、Constantin G. Daniliuc、Armido Studer
DOI:10.1021/jacs.3c01667
日期:2023.4.19
Enantioenriched chiral indoles are of high interest for the pharmaceutical and agrochemical industries. Herein, we present an asymmetric Fukuyama indolesynthesis through a mild and efficient radical cascade reaction to access 2-fluoroalkylated 3-(α-cyanobenzylated) indoles by stereochemical control with a chiral copper-bisoxazoline complex using 2-vinylphenyl arylisocyanides as radical acceptors and
对映体富集的手性吲哚引起了制药和农用化学工业的高度关注。在此,我们提出了一种不对称福山吲哚合成方法,通过温和有效的自由基级联反应,通过手性铜-双恶唑啉络合物的立体化学控制,使用2-乙烯基苯基芳基异氰化物作为自由基受体和氟烷基,获得2-氟烷基化的3-(α-氰基苄基化)吲哚。碘化物作为 C-自由基前体。异腈部分的自由基加成、5 -exo -trig 环化和 Cu 催化的立体选择性氰化为目标吲哚提供了优异的对映选择性和良好的产率。由于需要区分的两个芳基取代基具有相似的电子和空间性质,氰基二芳基甲烷立体中心的对映选择性构建极具挑战性。机理研究揭示了负非线性效应,允许提出一个模型来解释立体化学结果。证明了对映体富集的 3-(α-氰基苄基化)吲哚作为手性色胺、吲哚-3-乙酸衍生物和三芳基甲烷的中心的可扩展性和潜在用途,并公开了天然产物类似物的正式合成。