A facile regio- and stereoselectivesynthesis of functionalized pyrrolidines, spiropyrrolidines, and spiropyrrolizidines using the Baylis-Hillman adducts derived from nitroolefins via intermolecular [3+2]-cycloaddition reaction is reported. Baylis-Hillman reaction - intermolecular [3+2] cycloaddition - azomethineylides - 1,3-dipolar cycloaddition - pyrrolidines - spiro compounds
Organocatalytic desymmetrization of cyclic meso-anhydrides through enantioselective alcoholysis with functionalized primary nitroallylic alcohols
作者:Yan ming Chen、Mamatha Amireddy、Kwunmin Chen
DOI:10.1016/j.tet.2014.10.008
日期:2014.11
The direct organocatalytic desymmetrization of cyclic meso-anhydrides was achieved by alcoholysis with nitroallylic alcohols. The reaction between primary nitroallylic alcohols and cyclic meso-anhydrides catalyzed by cinchonidine derived thiourea organocatalyst II (10 mol %) proceeded smoothly. The corresponding hemiesters were obtained in high chemical yields with high to excellent levels of stereoselectivity
A remarkable solvent effect on the reaction of 4-hydroxycoumarin with (E)-3-aryl-2-nitroprop-2-enol: Facile synthesis of highly substituted furo/pyrano[3,2-c]chromenes
作者:Shivendra Singh、Anvita Srivastava、Shaikh M. Mobin、Sampak Samanta
DOI:10.1039/c4ra10610e
日期:——
A remarkable solvent effect on the reaction of 4-hydroxycoumarin derivatives with (E)-3-aryl/hetero-aryl-2-nitroprop-2-enols has been observed in water and DMSO media. This result was employed for the straightforward syntheses of new functionalized furo/pyrano[3,2-c]chromenes in 63–93% yields and diasteromeric ratio up to ≤99 : 1. Moreover, a simple, mild, efficient and catalyst-free one-pot method
在水和DMSO介质中,已观察到对4-羟基香豆素衍生物与(E)-3-芳基/杂芳基-2-硝基丙-2-烯醇的反应具有显着的溶剂作用。该结果用于新型官能化的呋喃/吡喃并[3,2- c ]色烯的直接合成,产率为63-93%,非对映异构体比例最高为≤99:1。此外,该方法简单,温和,高效且无催化剂一锅法可能会为香豆素核上的呋喃/吡喃环的成环提供另一种合成策略。此外,水对该反应的速率和选择性(产物)显示出显着的积极作用。
First Synthesis of Bromo and Chloro Derivatives of Baylis-Hillman Adducts Derived from Nitroolefins: Application towards the Synthesis of a Dendrimer Core
For the first time Baylis-Hillman adducts derived from nitroolefins have been conveniently transformed into a novel class of building blocks, 1-[(E)-3-bromo-2-nitroprop-1-enyl]arenes and 1-[(E)-3-chloro-2-nitroprop-1-enyl]arenes, in very good yields via an SN2reaction using simple reaction conditions. Further application of these compounds has been demonstrated for the synthesis of tris[(E)-2-nitr
首次将衍生自硝基烯烃的Baylis-Hillman加合物首次方便地转化为一类新型的结构单元,即1-[(E)-3-溴-2-硝基-2-硝基丙-1-烯基]芳烃和1-[(E)通过使用简单的反应条件的S N 2反应,以非常好的收率得到-3-氯-2-硝基丙-1-基]芳烃。这些化合物的进一步应用已经证明可以合成三[(E)-2-硝基-3-芳基烯丙基]胺作为树枝状聚合物核。 Baylis-Hillman反应-乙酸铵-硝基烯烃-氯化铁(III)-氢溴酸
Access to Substituted Carbazoles in Water by a One-Pot Sequential Reaction of α,β-Substituted Nitro Olefins with 2-(3-Formyl-1<i>H</i>-indol-2-yl)acetates
interesting new multifunctional carbazole scaffolds have been prepared in good to excellent yields by an organocatalytic one-pot two-step sequentialreaction between α-alkyl-β-substituted nitroolefins or α-alkyl-δ-substituted nitro-dienes and 2-(3-formyl-1H-indol-2-yl)acetates in water at room temperature followed by treatment with 2 n HCl under mild conditions. This one-pot, organocatalytic, oxidant-free