Remote Construction of N‐Heterocycles via 1,4‐Palladium Shift‐Mediated Double C−H Activation
摘要:
AbstractIn the past years, Pd0‐catalyzed C(sp3)−H activation provided efficient and step‐economical methods to synthesize carbo‐ and heterocycles via direct C(sp2)−C(sp3) bond formation. We report herein that a 1,4‐Pd shift allows access to N‐heterocycles which are difficult to build via a direct reaction. It is shown thato‐bromo‐N‐methylanilines undergo a 1,4‐Pd shift at theN‐methyl group, followed by intramolecular trapping by C(sp2)−H or C(sp3)−H activation at another nitrogen substituent and remote C−C bond formation to generate biologically relevant isoindolines and β‐lactams. The product selectivity is influenced by the employed ligand, with NHCs favoring the product of remote C−C coupling against products arising from direct C−C coupling and N‐demethylation.
合成了一系列 1,2,3-三唑结合的阳离子 Au(I) 催化剂,并通过 X 射线晶体学表征了它们的结构。变温核磁共振研究揭示了溶液中的动态三唑-金阳离子配位。反应曲线清楚地表明,这些新催化剂比文献报道的 Au 催化剂具有更好的热稳定性,包括 IPrAu x NTf(2)。通过应用这些催化剂,用反应性较低的内炔和未保护的脂肪胺实现了具有挑战性的分子间加氢胺化反应,在低催化剂负载的情况下获得了优异的产率。
A Highly Enantioselective Lewis Basic Organocatalyst for Reduction of <i>N</i>-Aryl Imines with Unprecedented Substrate Spectrum
作者:Zhouyu Wang、Xiaoxia Ye、Siyu Wei、Pengcheng Wu、Anjiang Zhang、Jian Sun
DOI:10.1021/ol060112g
日期:2006.3.2
L-Pipecolinic acid derived formamides have been developed as highly efficient and enantioselective Lewis basic organocatalysts for the reduction of N-aryl imines with trichlorosilane. Catalyst 4b afforded high isolated yields (up to 98%) and enantioselectivities (up to 96%) under mild conditions with an unprecedented substrate spectrum.
Silver-Catalyzed Alkyne Activation: The Surprising Ligand Effect
作者:Yijin Su、Mei Lu、Boliang Dong、Hao Chen、Xiaodong Shi
DOI:10.1002/adsc.201300785
日期:2014.3.10
An unexpected ligand effect was discovered in the silver(I)‐catalyzed alkyneactivation. For both aldehyde‐alkyne‐amine (A3) condensation and intermolecular alkynehydroamination, the type B complex (P:Ag=1:1) effectively promoted the reaction, while no reaction occurred with either no ligand or excess ligands under the identical conditions.
Indium-Catalyzed Hydroamination/Hydrosilylation of Terminal Alkynes and Aromatic Amines through a One-Pot, Two-Step Protocol
作者:Norio Sakai、Nobuaki Takahashi、Yohei Ogiwara
DOI:10.1002/ejoc.201402544
日期:2014.8
functioned as a single catalyst for two successive steps in a one-pot procedure. First, the hydroamination of alkynes with anilines took place to give the Markovnikov product. Then, hydrosilylation of the imine intermediates by treatment with a hydrosilane substrate afforded the corresponding secondary amines.
Triazole−Au(I) Complexes: A New Class of Catalysts with Improved Thermal Stability and Reactivity for Intermolecular Alkyne Hydroamination
作者:Haifeng Duan、Sujata Sengupta、Jeffrey L. Petersen、Novruz G. Akhmedov、Xiaodong Shi
DOI:10.1021/ja9041093
日期:2009.9.2
3-triazole-bound cationic Au(I) catalysts have been synthesized, and their structures have been characterized by X-ray crystallography. Variable-temperature NMR studies revealed dynamic triazole-Au cation coordination in solution. Reaction profiles clearly indicated that these new catalysts possess much better thermal stability than literature-reported Au catalysts, including IPrAu x NTf(2). By application
合成了一系列 1,2,3-三唑结合的阳离子 Au(I) 催化剂,并通过 X 射线晶体学表征了它们的结构。变温核磁共振研究揭示了溶液中的动态三唑-金阳离子配位。反应曲线清楚地表明,这些新催化剂比文献报道的 Au 催化剂具有更好的热稳定性,包括 IPrAu x NTf(2)。通过应用这些催化剂,用反应性较低的内炔和未保护的脂肪胺实现了具有挑战性的分子间加氢胺化反应,在低催化剂负载的情况下获得了优异的产率。
Decomplexation of (η-arene)(η-cyciopentadienyl)iron(<scp>II</scp>) hexafluorophosphates: a convenient one-pot arylation procedure
作者:Richard A. Brown、Sharon I. S. Fernando、Roger M. G. Roberts
DOI:10.1039/p19940000197
日期:——
light sensitive. Bipyridine gave much lower yields. Potassium tert-butoxide in pyridine or DMSO was found to be an excellent demetallating agent even with sterically crowded complexes. A one-pot arylation procedure was developed and extended to include a number of important heterocyclic derivatives. The mechanism of these decomplexation reactions is briefly addressed.