γ‐di‐aryl propanones. The salient feature of this strategy involves the sequential hydride transfer, regiospecific condensation, regiospecific dearylation, and aromatization under metal‐free reaction conditions. The synthesis of unsymmetricallysubstituted triphenylenes by oxidative coupling of the synthesized 1,2,4‐triaryl benzenes has also been demonstrated.
Pd and Ni complexes of a novel vinylidene β-diketimine ligand: Their application as catalysts in Heck coupling and alkyne trimerization
作者:Raghavendra Beesam、Dastagiri Reddy Nareddula
DOI:10.1002/aoc.3696
日期:2017.9
A β‐diketimine ligand with vinylidene substitution at γ‐carbon, CH2C(CH3CNAr)2 (Ar = 2,6‐diisopropylphenyl) (L2), was synthesized by treating β‐diketimine H2C(CH3CNAr)2 with n‐BuLi followed by paraformaldehyde. L2 formed the homobimetallic ether‐bridged β‐diketiminatecomplex [O(CH2‐β‐diketiminate)Pd(OAc)}2] (1) with (PdOAc)2. It also gave complexes [L2PdCl2] (2) and [L2NiBr2] (3) when treated with
Efficient Intermolecular [2 + 2 + 2] Alkyne Cyclotrimerization in Aqueous Medium Using a Ruthenium(IV) Precatalyst
作者:Victorio Cadierno、Sergio E. García-Garrido、José Gimeno
DOI:10.1021/ja066552k
日期:2006.11.1
bis(allyl)-ruthenium(IV) complex [Ru(eta3:eta3-C10H16)(mu-Cl)Cl}2] (C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl) was found to catalyze efficiently the [2 + 2 + 2] cyclization of terminal and internal alkynes in aqueous medium.
Iron-Catalyzed Cyclotrimerization of Terminal Alkynes by Dual Catalyst Activation in the Absence of Reductants
作者:Davide Brenna、Matteo Villa、Tim N. Gieshoff、Fabian Fischer、Marko Hapke、Axel Jacobi von Wangelin
DOI:10.1002/anie.201705087
日期:2017.7.10
metals under mild conditions is at the heart of sustainable synthesis. The cyclotrimerization of alkynes is a valuable atom‐efficient reaction in organic synthesis that is enabled by several metal catalysts, including iron. This study reports an effective iron‐catalyzed cyclotrimerization for the regioselective synthesis of 1,2,4‐substituted arenes (1 mol % catalyst, toluene, 20 °C, 5 min). A dual activation
Can the Ti(OiPr)<sub>4</sub>/<i>n</i>BuLi combination of reagents function as a catalyst for [2+2+2] alkyne cyclotrimerisation reactions?
作者:Gabriela Siemiaszko、Yvan Six
DOI:10.1039/c8nj04931a
日期:——
Catalysis of the cyclotrimerisation of alkynes with the Ti(OiPr)4/nBuLi system was studied, leading to the development of a particularly convenient and reliable protocol. This method allows the [2+2+2] cycloadditionreaction to proceed within a few minutes under microwave conditions, with generally good selectivity from a variety of aromatic and aliphatic alkynes.
研究了用Ti(OiPr)4 / n BuLi体系催化炔烃的环三聚反应,从而开发了一种特别方便和可靠的方案。该方法允许[2 + 2 + 2]环加成反应在微波条件下在几分钟之内进行,对各种芳族和脂族炔烃的选择性通常都很好。