Arylalkene Synthesis via Decarboxylative Cross-Coupling of Alkenyl Halides
摘要:
A bimetallic catalyst system generated from readily available palladium(II) and copper(I) salts, 1,10-phenanthroline and tri-1-naphthylphosphine was found to efficiently mediate the decarboxylative cross-coupling of alkenyl bromides and chlorides with aromatic carboxylates. It allows the regiospecific synthesis of a broad range of aryl- and heteroarylalkenes in high yields.
Iron-Catalyzed Reductive Coupling of Nitroarenes with Olefins: Intermediate of Iron–Nitroso Complex
作者:Heng Song、Zhuoyi Yang、Chen-Ho Tung、Wenguang Wang
DOI:10.1021/acscatal.9b03604
日期:2020.1.3
Using a single half-sandwich iron(II) compound, Cp*Fe(1,2-Ph2PC6H4S)(NCMe) (Cp*– = C5Me5–, 1) as a catalyst, reductivecoupling of nitroarenes with olefins has been achieved by a well-defined iron(II)/(EtO)3SiH system. Through either inter- or intramolecular reductivecoupling, various branched amines and indole derivatives have been directly synthesized in one-pot. Mechanistic studies showed that
使用单一的半夹心铁(II)化合物作为催化剂,将Cp * Fe(1,2-Ph 2 PC 6 H 4 S)(NCMe)(Cp * – = C 5 Me 5 –,1)作为催化剂,进行还原偶联明确定义的铁(II)/(EtO)3 SiH体系可实现硝基芳烃与烯烃的合成。通过分子间或分子内的还原偶联,已经在一锅中直接合成了各种支链胺和吲哚衍生物。机理研究表明,催化作用是由铁(II)催化剂与硅烷活化硝基芳烃而引发的,从而生成用于C-N键偶联的铁-亚硝基芳烃中间体。
Aqueous Titanium Trichloride Promoted Reductive Cyclization of
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‐Nitrostyrenes to Indoles: Development and Application to the Synthesis of Rizatriptan and Aspidospermidine
TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)–H amination process. A range of functions such as halides (Cl, Br), carbonyl (ester, carbamate), cyano, hydroxy, and amino groups were tolerated. From β,β‐disubstituted o‐nitrostyrenes, 2,3‐disubstituted indoles were formed by a domino reduction/cyclization/migration process. Mild conditions, simple experimental procedure
A two‐step synthesis of structurally diverse pyrrole‐containingbicyclic systems is reported. ortho‐Nitro‐haloarenes coupled with vinylic N‐methyliminodiacetic acid (MIDA) boronates generate ortho‐vinyl‐nitroarenes, which undergo a “metal‐free” nitrene insertion, resulting in a new pyrrole ring. This novel synthetic approach has a wide substrate tolerance and it is applicable in the preparation of
Counterion Control of
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‐BuO‐Mediated Single Electron Transfer to Nitrostilbenes to Construct
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‐Hydroxyindoles or Oxindoles
作者:Yingwei Zhao、Haoran Zhu、Siyoung Sung、Donald J. Wink、Joseph M. Zadrozny、Tom G. Driver
DOI:10.1002/anie.202104319
日期:2021.8.23
tert-Butoxide unlocks new reactivity patterns embedded in nitroarenes. Exposure of nitrostilbenes to sodium tert-butoxide was found to produce N-hydroxyindoles at room temperature without an additive. Changing the counterion to potassium changed the reaction outcome to yield solely oxindoles through an unprecedented dioxygen-transfer reaction followed by a 1,2-phenyl migration. Mechanistic experiments
Synthesis of nitrodienes, nitrostyrenes, and nitrobiaryls through palladium-catalyzed couplings of β-nitrovinyl and o-nitroaryl thioethers
作者:Gardner S. Creech、Ohyun Kwon
DOI:10.1039/c3sc50773d
日期:——
A highly efficient, base-free, mild protocol for the palladium-catalyzed, copper-activated desulfitative couplings of vinyl and aryl β-nitrothioethers generates a wide variety of conjugated nitroorganics. Orthogonality to traditional SuzukiâMiyaura coupling is demonstrated, as well as synthetic utility, through reductive Cadogan cyclization, for the formation of indoles, carbazoles, and pyrroles.