Iron(III)‐Catalyzed Arylation of Spiro‐Epoxyoxindoles with Phenols/Naphthols towards the Synthesis of Spirocyclic Oxindoles

An efficient and highly regioselective iron(III)‐catalyzed Friedel–Crafts‐type arylation of spiro‐epoxyoxindoles with phenols was developed for rapid access to 3‐(3‐indolyl)‐oxindole‐3‐methanols, which could be further elaborated into benzofuranyl‐spirooxindoles under Mitsunobu conditions. When spiro‐epoxyoxindoles were reacted with naphthols in the presence of a catalytic amount of FeCl₃?6 H₂O in dichloromethane, they underwent a tandem Friedel–Crafts‐type arylation and O‐cyclization to yield novel naphthofuranyl‐spirooxindoles in excellent yields. This method is applied to enable the efficient and highly regioselective synthesis of a small‐molecule inhibitor of the sodium channel Na_v1.7 (±)‐XEN402, which is currently in a phase IIb clinical trial for the treatment of pain.     

新型3-五元碳环螺环氧化吲哚类化合物的合成及其抗人白血病细胞活性

以氧化吲哚与邻芳基二甲醛为原料,经Knoevenagel缩合(或Michael,环化反应),制得7个3-五元碳环螺环氧化吲哚(4a~4c,产率67%~86%,d/r值4∶1~10∶1)和4d~4g;4d~4g与哌啶(或四氢吡咯)和多聚甲醛经胺甲基化反应,合成了4个3-五元碳环螺环氧化吲哚(5d~5g),产率55%~67%,d/r值10∶1~20∶1,其结构经~1H NMR,~(13)C NMR和HR-MS(ESI-TOF)表征。采用MTT法研究了4a~4c和5d~5g对人白血病细胞(K562)的体外抗肿瘤活性。结果表明:4b,5d和5f对K562抑制活性较好,IC50分别为29.3μmol·L~(-1),27.4μmol·L~(-1)和34.2μmol·L~(-1),与阳性对照药顺铂(26.8μmol·L~(-1))相当。     

钯催化吡咯环内共轭双键的Heck反应

基于迁移插入策略,研究了钯催化吡咯环内共轭双键的分子内Heck反应.在温和的反应条件下,以良好至优异的收率合成了一系列含有二氢吡咯及2-吲哚酮结构的螺杂环化合物.同时,以八氢联萘酚衍生的亚磷酰胺为手性配体,初步探索该对映选择性反应,获得中等水平的对映体过量值.     

Dual complex of amylose with iodine and magnetite nano‐crystallites: Enhanced superparamagnetic and catalytic performance for synthesis of spiro‐oxindoles

Mass magnetization of magnetite nanoparticles was enhanced by disassembling and encapsulating their building nano‐crystallites with water‐soluble starch. Incorporation of iodine into the as‐prepared nano‐conglomerate led to formation of a ternary nano‐complex and further enhancement of its superparamagnetic susceptibility. As an additional evidence for the anomalously heightened superparamagnetic property, the ternary nano‐complex showed lower magnetic remanence and coercivity than the pristine magnetite it was made from. These findings were ascribed to significant changes in, at least, size of the magnetite nano‐crystallites during formation of the nano‐composite. A significant enhancement was also observed in the catalytic efficiency of the nano‐composite, as was successfully exemplified in the synthesis of some novel spiro[oxindole‐dihydropyridine]s via a three‐component reaction between isatins, furan‐2,4(3H,5H)‐dione and aminouracils ‘on water’.     

Allylation and alkylation of oxindoleketimines via imine umpolung strategy

When treated with an alkoxide base like t-BuOK in aprotic solvent, N-diphenylmethyl imino oxindoles, made conveniently through condensation of corresponding isatins with N-diphenylmethyl amine, are deprotonated to form azaallyl anions. Allylation and alkylation of this type of intermediates proceed smoothly with diverse C-electrophiles. Acidic work up finishes 3-amino-3-allyl/alkyl oxindoles. The overall transformation equals to an umpolung process at the C3 of isatins.     

1,2,3‐Triazole derivatives of 3‐ferrocenylidene‐2‐oxindole: Synthesis,characterization, electrochemical and antimicrobial evaluation

A series of bioactive, triazole‐linked benzyl, aryl, sugar and aliphatic conjugates of 3‐ferrocenylidene‐oxindole have been synthesized. A facile 1,3‐dipolar‐Huisgen coupling reaction of the respective azides with the 3‐ferrocenylidene‐oxindole N‐propargyl moiety ( 3 ) gave the corresponding conjugates ( 5a–n ). All the newly synthesized compounds ( 5a–n ) were characterized by ¹H‐NMR, ¹³C‐NMR, HRMS, Fourier transform‐infrared spectroscopy and elemental analysis. The UV–Vis and electrochemical studies of these compounds were performed in dimethylsulfoxide solutions. The structure of compound ( 3 ) was determined by single crystal X‐ray diffraction study. These compounds exhibited moderate to good antimicrobial activity against Gram‐positive and Gram‐negative strains.     

One-pot approach for the stereoselective synthesis of spirocyclopropyl oxindoles from isatins and arsonium salts

A one-pot approach for highly stereoselective synthesis of spirocyclopropyl oxindoles 3 with good to excellent yields from the reaction of isatins 1 and arsonium salts 2 in the presence of K₂CO₃ is described. The structure of product 3 was confirmed by ¹H NMR, ¹³C NMR, IR, MS, EA, and X-ray diffraction as well.     

On Water: Brφnsted Acidic Ionic Liquid[(CH2)4SO3HMIM][HSO4]Catalysed Synthesis of Oxindoles Derivatives

Some oxindoles derivatives are synthesized from the condensation of indoles with isatins in the presence of green and recycable catalyst [(CH₂)₄SO₃HMIM][HSO₄] in water at room temperature.