Remote Carboxylation with a Nickel Catalyst

 

 https://www.nature.com/nature/journal/v545/n7652/abs/nature22316.html

Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide

• Francisco Juliá-Hernández,
• Toni Moragas,
• Josep Cornella
• & Ruben Martin

Catalytic carbon–carbon bond formation has enabled the streamlining of synthetic routes when assembling complex molecules¹. It is particularly important when incorporating saturated hydrocarbons, which are common motifs in petrochemicals and biologically relevant molecules. However, cross-coupling methods that involve alkyl electrophiles result in catalytic bond formation only at specific and previously functionalized sites². Here we describe a catalytic method that is capable of promoting carboxylation reactions at remote and unfunctionalized aliphatic sites with carbon dioxide at atmospheric pressure. The reaction occurs via selective migration of the catalyst along the hydrocarbon side-chain³ with excellent regio- and chemoselectivity, representing a remarkable reactivity relay when compared with classical cross-coupling reactions. Our results demonstrate that site-selectivity can be switched and controlled, enabling the functionalization of less-reactive positions in the presence of a priori more reactive ones. Furthermore, we show that raw materials obtained in bulk from petroleum processing, such as alkanes and unrefined mixtures of olefins, can be used as substrates. This offers an opportunity to integrate a catalytic platform en route to valuable fatty acids by transforming petroleum-derived feedstocks directly⁴.

New air stable cationic methallyl Ni complexes bearing imidoyl-indazole carboxylate ligand: Synthesis, characterization and their reactivity towards ethylene

New air stable cationic methallyl Ni complexes bearing imidoyl-indazole carboxylate ligand: Synthesis, characterization and their reactivity towards ethylene

Alan R. Cabreraa, d, , ,
Ivan Martineza,
Constantin G. Daniliucb,
Griselda B. Gallandc,
Cristian O. Salasa,
Rene S. Rojasa,
a Nucleus Millennium of Chemical Processes and Catalysis, Faculty of Chemistry, Pontificia Universidad Católica de Chile, Casilla 306, Santiago, Chile
b Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149 Münster, Germany
c Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
d Universidad Bernardo O Higgins, Departamento de Ciencias Químicas y Biológicas, Laboratorio de Bionanotecnología, General Gana 1702, Santiago, Chile
Received 4 December 2015, Revised 23 December 2015, Accepted 27 December 2015, Available online 31 December 2015







Three new neutral N,N imidoyl-indazole ligands with a methoxycarbonyl functional group (1–3) and three new air-stable cationic methallyl nickel complexes (4–6) were prepared. These compounds were characterized by NMR, FT-IR and elemental analyses. In addition, compounds 1, 2, 3 and 4 were analyzed using X-ray diffraction. An evaluation of the reactivity of complexes 4–6 toward ethylene was conducted by using 5 equivalents of B(C6F5)3. At 1 bar of ethylene and 20 °C, only complexes 4 and 6 were able to produce butene, showing unusual air stability and dimerizing ethylene even after exposure to air for 48 h. By increasing the pressure to 12 bar at 20 °C, complex 6 showed a catalytic activity of 401 Kg product (mol Ni)−1 h−1, producing a low molecular weight polyethylene (26.6 Kg/mol) with almost exclusively methyl branches (2.3 mol%). By increasing the temperature to 60 °C at 12 bar of ethylene, the system 6/B(C6F5)3 increased its catalytic activity to 487 Kg product (mol Ni−1) h−1, but produced a significant decrease in the molecular weight of the polymer (1.8 Kg/mol) and a broad distribution of branches.

Neutral Nickel Catalysts for Olefin Homo- and Copolymerization: Relationships between Catalyst Structures and Catalytic Properties

Neutral Nickel Catalysts for Olefin Homo- and Copolymerization: Relationships between Catalyst Structures and Catalytic Properties

Hongliang Mu,† Li Pan,*,‡ Dongpo Song,§ and Yuesheng Li*,†,‡
† State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China ‡ School of Material Science and Engineering, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China § Department of Polymer Science and Engineering, University of Massachusetts Amherst, 120 Governors Drive, Amherst, Massachusetts 01003, United States

Chemical Reviews: http://pubs.acs.org/doi/pdf/10.1021/cr500370f
DOI: 10.1021/cr500370f

Abstract: As one milestone in the history of polymerization chemistry, the work of Ziegler and Natta has led to the rapid commercialization of transition metal catalysts for the production of high molecular weight polyolefins.1−4 However, the heterogeneous nature of Ziegler−Natta catalytic systems has hindered better understanding of the polymerization mechanisms, resulting in great difficulties in the design of new catalysts. The advance of homogeneous single-site metallocene catalysts together with the discovery of methylaluminoxane (MAO) is a real breakthrough in understanding the relationship between catalyst structure and catalytic behaviors in olefin polymerization. A more precise control over polymer microstructures has been achieved through modification of the metallocene catalytic systems,5−7 which greatly invigorates the development of new single-site catalysts (postmetallocene catalysts) based on both early and late transition metals.8−17

Progress in Synthesis of Highly Active and Stable Nickel-Based Catalysts for Carbon Dioxide Reforming of Methane

Prof. Sibudjing Kawi, Dr. Yasotha Kathiraser, Dr. Jun Ni, Dr. Usman Oemar, Dr. Ziwei Li, Dr. Eng Toon Saw

Abstract

In recent decades, rising anthropogenic greenhouse gas emissions (mainly CO₂ and CH₄) have increased alarm due to escalating effects of global warming. The dry carbon dioxide reforming of methane (DRM) reaction is a sustainable way to utilize these notorious greenhouse gases. This paper presents a review of recent progress in the development of nickel-based catalysts for the DRM reaction. The enviable low cost and wide availability of nickel compared with noble metals is the main reason for persistent research efforts in optimizing the synthesis of nickel-based catalysts. Important catalyst features for the rational design of a coke-resistant nickel-based nanocatalyst for the DRM reaction are also discussed. In addition, several innovative developments based on salient features for the stabilization of nickel nanocatalysts through various means (which include functionalization with precursors, synthesis by plasma treatment, stabilization/confinement on mesoporous/microporous/carbon supports, and the formation of metal oxides) are highlighted. The final part of this review covers major issues and proposed improvement strategies pertaining to the rational design of nickel-based catalysts with high activity and stability for the DRM reaction.

http://onlinelibrary.wiley.com/doi/10.1002/cssc.201500390/full

Nickel-catalyzed arylation of heteroaryl-containing diarylmethanes: exceptional reactivity of the Ni(NIXANTPHOS)-based catalyst

http://pubs.rsc.org/en/Content/ArticleLanding/2016/SC/C5SC03704B?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FSC+%28RSC+-+Chem.+Sci.+latest+articles%29#!divAbstract


Nickel-catalyzed arylation of heteroaryl-containing diarylmethanes: exceptional reactivity of the Ni(NIXANTPHOS)-based catalyst
Xinyu Cao,ab Sheng-Chun Sha,b Minyan Li,b Byeong-Seon Kim,b Catherine Morgan,b Rudan Huang,a Xiaodong Yangc and Patrick J. Walsh*b

Show Affiliations
Chem. Sci., 2016, Advance Article
DOI: 10.1039/C5SC03704B
Received 30 Sep 2015, Accepted 07 Oct 2015
First published online 26 Oct 2015





Nickel(0)-catalyzed cross-coupling of heteroaryl-containing diarylmethanes with both aryl bromides and chlorides has been achieved. The success of this reaction relies on the introduction of a unique nickel/NIXANTPHOS-based catalyst system, which provides a direct route to triarylmethanes from heteroaryl-containing diarylmethanes. Reactivity studies indicate the Ni(NIXANTPHOS)-based catalyst exhibits enhanced reactivity over XANTPHOS derivatives and other Ni(phosphine)-based catalysts in the reactions examined.