Palladium-Catalyzed Synthesis of <i>N</i>
-Cyclohexyl Anilines from Phenols with Hydrazine or Hydroxylamine via N-N/O Cleavage
作者:Jiang-Sheng Li、Zihang Qiu、Chao-Jun Li
DOI:10.1002/adsc.201700712
日期:2017.10.25
Direct access to amines from biomass‐based phenols via deoxygenative transformation remains greatly challenging in organic synthesis. Herein, we present a palladium‐catalyzed deoxygenative amination of phenols (and their benzyl ether) with hydrazine as nitrogen source. The hydroxylamine/formic acid can be substituted for hydrazine in some cases. This deoxyamination features the involvement of a complex
Formal Cross-Coupling of Diaryl Ethers with Ammonia by Dual C(Ar)–O Bond Cleavages
作者:Dawei Cao、Huiying Zeng、Chao-Jun Li
DOI:10.1021/acscatal.8b02214
日期:2018.9.7
inorganic chemical. Herein, we report a direct conversion of diaryl ethers and ammonia into aniline derivatives and arenes, providing a model for selective lignin 4-O-5 linkage modification and PPO recycling with inexpensive ammonia. Both symmetrical and unsymmetrical diaryl ethers were successfully cross-coupled with ammonia via dual C(Ar)–O bond cleavages, generating the corresponding cyclohexylanilines
In the presence of a supported gold–palladium alloy nanoparticle catalyst (Au–Pd/Al2O3), various kinds of N-substituted anilines can be synthesized from non-aromatic compounds.
Method to convert lignin 4-O-5 diaryl ethers and their model compounds into organic chemicals
申请人:LANZHOU UNIVERSITY
公开号:US10766851B1
公开(公告)日:2020-09-08
It is provided a method of converting a diaryl ether source such as lignin and/or polyphenylene oxide (PPO) containing 4-O-5 linkages and an inorganic chemical such as ammonia into an organic compound, comprising reacting said diaryl ether source with the inorganic chemical in presence of a catalyst, preferably palladium, transforming the 4-O-5 linkages of said diaryl ether source into the organic compound. It is provided a palladium-catalyzed synthesis of aniline derivatives from 4-O-5 linkage lignin model compounds and cheap industrial inorganic chemical ammonia via dual C(Ar)—O bond cleavage.
Cascade hydrogenation of nitrobenzene to dicyclohexylamine with Pd/γ-Al2O3: The role of acid sites
作者:Xiang Li、Xiaomin Ren、Maodi Wang、Qihua Yang
DOI:10.1016/j.apcata.2022.118835
日期:2022.8
site could promote the coupling reaction. By analyzing the correlation between hydrogenation activity and DCHA selectivity, it was found that the matched rate of hydrogenation and cross-coupling is the keyfactor to achieve highselectivity. This study may open a new avenue for the hydrogenation of nitroarenes to DCHA by regulating the acidity of supports and the reaction conditions.
由于交叉偶联反应(生成 DCHA)和加氢反应(生成副产物)的竞争,硝基苯 (NB) 直接加氢生成二环己胺 (DCHA) 是一种绿色但具有挑战性的工艺。在这里,我们报告说,通过调整负载型 Pd 催化剂的酸度,可以大大增强与所需 DCHA 的交叉偶联反应。发现负载在具有中等酸性的商业 γ-Al 2 O 3 (γ-Al 2 O 3-Com ) 上的 Pd NPs 比在中性 SBA-15 或强酸性 γ-Al 2 O 3上负载的选择性更高。纳米棒。酸性位点的存在可以促进偶联反应。通过分析加氢活性与DCHA选择性之间的相关性,发现加氢和交叉偶联的匹配率是实现高选择性的关键因素。该研究可能通过调节载体的酸度和反应条件为硝基芳烃加氢制DCHA开辟一条新途径。