The catalytic activity and stability of BF3 complexes with the lower carboxylic acids in the carbonylation of olefins and alcohols by carbon monoxide

Conclusions BF₃ Complexes with acetic or propionic acid are highly active and stable catalysts for the carbonylation of olefins and alcohols and may be used repeatedly without lowering the initial activity.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1314–1317, June, 1976.     

Photopromoted Carbonylation of Olefins with Carbon Dioxide by Transition Metal Complexes Catalysis

The carbonylation of olefins is important and essential methods to synthesize organic compounds,Which requires high temperature (150-200℃) and high pressure (10~20MPa) in addition to precious metal complex catalysts (such as Ru,Rh, Ir)^[1], In recent years photopromoted organic syntheses have received more and more attentions that were called environmentally friendly technique because of their ambient reaction conditions,high reactivities and selectivities and a little pollution^[2]. Photopromoted carbonylation can be completed in ambient conditions and by non-precious complexes catalysts, and especially photopromoted methoxycarbonylation of olefins could give better results^[3,4]. In previous papers we have established that the methoxycarbonylation of olefins with carbon dioxide could be carried out in place of carbon monoxide.     

一氧化碳参与不饱和烃类化合物羰基化反应的研究进展

不饱和烃类化合物的羰基化反应是指在过渡金属催化剂存在条件下, 将一氧化碳(CO)分子以羰基的形式插入到烯烃(或者炔烃)与不同的亲核试剂中, 合成更高附加值化学品的转化过程. 本文综合评述了羰基化反应合成高附加值化学品的重要性, 介绍了几种不同类型的羰基化反应(氢甲酰化反应、 氢酯化反应、 氢酰胺化反应和氢羧基化反应)在发展新型催化剂体系及高效合成目标产物方面的研究进展, 并对羰基化反应存在的问题及未来发展方向和趋势进行了展望.     

Carbon monoxide as a reagent: A report on the role of N-heterocyclic carbene (NHC) ligands in metal-catalyzed carbonylation reactions

This report is a focused and critical essay on the effectiveness of M–NHC catalysts in reactions that specifically utilize carbon monoxide as a C1-carbon source. NHC ligands are touted as excellent trialkylphosphine (PR₃) mimics and are purported to improve existing phosphine based catalysts. One premise for using NHCs is that the need for excess ligand could be obviated in certain reactions. If true, then reactions involving CO as a reagent should be improved when a M–NHC complex is employed. Herein is a compilation of results that feature CO as a reagent in reactions such as: hydroformylation, hydroaminomethylation, carbonylation of aryl halides, oxidative carbonylation of amino and phenolic compounds, and the copolymerization of alkenes and CO. The aim of the report is to highlight reactions in which the ancillary NHC ligand is beneficial, detrimental, ineffective, or inconclusive in promoting the desired chemistry.     

Carbonylation of Alkynes,Alkenes and Alcohols using Metal Complex Catalysts

Carbonylation of olefins, alcohols and halides using homogeneous as well as heterogeneous catalysts has been discussed. Highlights of contributions on the activity, selectivity and stability of catalysts for carbonylation reactions are discussed. Kinetics and mechanism including characterization of the intermediate catalytic species has also been reviewed. The performance of anchored Pd complexes on mesoporous supports (MCM-41 and MCM-48), water soluble Pd complexes and supported Pd catalysts in carbonylation of aryl alcohols and olefins has been discussed in the context of catalyst-product separation. Some aspects of kinetic modelling and reaction engineering of these multiphase catalytic reactions have also been reviewed.     

Review of Acetic Acid Synthesis from Various Feedstocks Through Different Catalytic Processes

Acetic acid (AA) has been largely used with a wide range of applications such as a raw material for a synthesis of vinyl acetate monomer, cellulose acetate or acetate anhydrate, acetate ester and a solvent for a synthesis of terephthalic acid and so on. The present paper briefly summarizes the commercialized chemical processes with their Rh or Ir-based catalytic systems in a liquid-phase carbonylation reaction such as Monsanto, Cativa and Acetica processes. In addition, some alternative catalytic systems such as heterogeneous catalysts to produce AA by direct oxidation or indirect carbonylation of dimethyl ether through BP-SaaBre process in a gas-phase reaction to solve some problems such as a difficult separation of homogeneous catalysts in a corrosive reaction medium. Some home-made heterogeneous catalysts such as a rhodium incorporated graphitic carbon nitride (Rh-g-C₃N₄) and some heterogenized homogeneous catalysts using the supports of tungsten carbide, iron oxide or graphitic carbon nitride containing rhodium complexes were also introduced for the synthesis of AA through a liquid-phase methanol carbonylation reaction to effectively solve the leaching problem of active rhodium metal as well as to mitigate the separation problem of homogeneous catalysts.     

Direct Synthetic Processes for Cyclic Carbonates from Olefins and CO<Subscript>2</Subscript>

This short review presents the recent developments in the direct synthesis of cyclic carbonates from olefins and CO₂. The straightforward synthesis of cyclic carbonates from olefins instead of epoxides, also called one-pot “oxidative carboxylation” of olefins, can be viewed as the coupling of two sequential reactions of epoxidation of olefins and CO₂ cycloaddition to epoxides formed. The facile synthetic approach would make carbonate synthesis simpler and even cheaper with industrial potential from environmental and economic points of view. Some progresses have been made on this direct synthetic reaction for cyclic carbonates with homogeneous and heterogeneous catalysts, however, this reaction system is still at a preliminary stage. Among the catalysts reported, only a few can be considered as effective for the direct oxidative carboxylation of olefins to cyclic carbonates. Thus active and selective catalysts should be explored to put the direct synthesis of cyclic carbonates into practical applications.     

Palladium-catalyzed difluoroalkylative carbonylation of styrenes toward difluoropentanedioates

The introduction of fluorine atoms into organic molecules is an attractive but challenging topic. In this work, an interesting palladium-catalyzed difluoroalkylative carbonylation of aryl olefins has been developed. A wide range of aryl olefins were transformed into the corresponding difluoropentanedioate compounds with good functional-group tolerance and excellent regioselectivity. Inexpensive ethyl bromodifluoroacetate acts both as a difluoroalkyl precursor and a nucleophile here. Additionally, a scale–up reaction was also performed successfully, and further transformations of the obtained product were shown as well.

An interesting palladium-catalyzed difluoroalkylative carbonylation of aryl olefins has been developed. A wide range of aryl olefins were transformed into the corresponding difluoropentanedioate compounds with good functional-group tolerance and excellent regioselectivity.     

钯催化烯烃不对称羰基化反应的研究进展

钯催化烯烃不对称羰基化反应是一种合成手性羰基化合物的有效方法之一,综述了近年来钯催化烯烃不对称羰基化反应的最新研究进展,重点讨论了配体、催化体系、反应条件等因素对烯烃羰基化反应的影响,并对烯烃不对称羰基化反应的区域选择性和对映选择性以及可能的反应机理进行了探讨.     

Polymerization of 4‐methylpentene and vinylcyclohexane by amine bis(phenolate) titanium and zirconium complexes

The polymerization of the substituted olefins 4‐methylpentene and vinylcyclohexane by dibenzyl titanium and zirconium complexes of three amine bis(phenolate) ligands is reported. The ligands featured a dimethylamino side‐arm donor and either electron‐withdrawing (Cl and Br) or methyl phenolate substituents. After activation with B(C₆F₅)₃, the zirconium catalysts exhibited a higher activity than the titanium catalysts toward these bulky olefins. Very high weight‐average molecular weight poly(4‐methylpentene) was obtained with the zirconium catalysts. The zirconium catalysts were employed in 1‐hexene polymerization, and their activity was found to be the highest ever reported for catalysts of the amine bis(phenolate) family. The catalysts featuring methyl phenolate substituents showed a higher activity toward these substituted olefins than the electron‐poor catalysts; this trend was opposite to their activity toward 1‐hexene. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1136–1146, 2006     

Semicorrin metal complexes as enantioselective catalysts. Part 2. Enantioselective cyclopropane formation from olefins with diazo compounds catalyzed by chiral (semicorrinato)copper complexes

Copper complexes of chiral, C₂-symmetric semicorrin ligands were found to be efficient catalysts for the cyclopropane formation from olefins with diazo compounds. In the presence of 1 mode-% of catalyst, alkyl diazoacetates reacted smoothly with terminal olefins such as styrene, butadiene, and 1-heptene to give the corresponding optically active cyclopropanecarboxylic-acid derivatives (Table 1 Scheme 2). With one of the catalysts, enantioselectivities up to 97% ee were obtained (Table 2). Usually, the reactions were carried out using bis(semicorrinato)copper(II) complexes as precatalysts. In order to produce active catalysts, these complexes had to be activated first by heating in the presence of diazoacetate or by treatment with phenylhydrazine. Experiments with (semicorrinato)copper(I) complexes, prepared in situ from copper(I) tert-butoxide (Scheme 4), suggest that the actual catalyst is a [mono(semicorrinato)]copper(I).     

Catalytic pyrolysis of HDPE in continuous mode over zeolite catalysts in a conical spouted bed reactor

A study has been carried out using HZSM-5, HY and Hβ zeolite-based catalysts in the pyrolysis of high density polyethylene (HDPE) continuously fed into a conical spouted bed reactor (CSBR) at 500 °C and atmospheric pressure, with the aim being to assess the yields and composition of the main products (both light olefins and automotive fuel hydrocarbons). Product streams have been grouped into seven lumps: light olefins (C₂–C₄) and light alkanes (<C₄) in the gas fraction, the liquid fraction consisting of three lumps (non-aromatic C₅–C₁₁ compounds, single-ring aromatics and C₁₁₊ hydrocarbons), wax and coke. The results are compared with those already obtained in thermal pyrolysis in a CSBR and with those obtained in the literature using catalysts in bubbling fluidized beds. HZSM-5 zeolite-based catalyst is very selective to light olefins, ≈58 wt% once equilibrated; whereas high yields of non-aromatic C₅–C₁₁ products (around 45 wt%) are obtained with Hβ and HY zeolite-based catalysts. Wax yield increases as reactions proceed, especially with HY and Hβ zeolite-based catalysts, due to catalyst deactivation by coke formation. Product distribution with the different catalysts and their evolution throughout continuous operation by feeding HDPE is explained according to the different properties of the zeolites used.     

Calcium‐Based Lewis Acid Catalysts

Recently, Lewis acidic calcium salts bearing weakly coordinating anions such as Ca(NTf₂)₂, Ca(OTf)₂, CaF₂ and Ca[OCH(CF₃)₂]₂ have been discovered as catalysts for the transformation of alcohols, olefins and carbonyl compounds. High stability towards air and moisture, selectivity and high reactivity under mild reaction conditions render these catalysts a sustainable and mild alternative to transition metals, rare‐earth metals or strong Brønsted acids.     

Acylation of five-membered N-heteroaromatic compounds by ruthenium carbonyl-catalyzed direct carbonylation at a C-H bond

The ruthenium-catalyzed carbonylation at the C-H bond of five-membered N-heteroaromatic compounds is described. The reaction of imidazoles with CO and olefins in toluene in the presence of a catalytic amount of Ru(3)(CO)(12) results in carbonylation of the C-H bond at the 4-position (adjacent to the sp(2)-nitrogen) of the imidazole ring to give acylated imidazoles in good to high yields. A wide range of olefins can be utilized in the carbonylation reaction, and a variety of functional groups are compatible under the reaction conditions. Other five-membered N-heteroaromatic compounds, such as pyrazoles, oxazoles, and thiazoles, can also be used for the carbonylation reaction, and in all cases, carbonylation takes place exclusively at a C-H bond alpha to the sp(2) nitrogen. The reactivity of the five-membered heterocycles corresponds to the pK(a) of the conjugate acid of these heterocycles. The higher the pK(a) of the substrate, the higher is the reactivity. This indicates that the pK(a) values are related to the ability of the nitrogen atom in the substrates to coordinate to a ruthenium center. The coordination of the substrates to the ruthenium center in the catalyst complex is a necessary prerequisite for the carbonylation to proceed.     

Catalytic Carbonylation and Carboxylation of Organosulfur Compounds via C−S Cleavage

Transition‐metal‐catalyzed carbonylation with CO gas occupies a privileged position in organic synthesis for the synthesis of carbonyl compounds. Although this attractive and useful chemistry has led many researchers to investigate carbonylative transformations of various organic (pseudo)halides, C?S‐cleaving carbonylation of organosulfur compounds has been fairly limited. Recently, a broad spectrum of C?S‐cleaving transformations has been emerging in the field of cross‐coupling. In light of the importance of carbonyl compounds as well as considerable advancement for employing organosulfur compounds as competent surrogates of (pseudo)halides, carbonylative transformations of C?S bonds should be of high value. This Minireview focuses on catalytic C?S carbonylation of organosulfur compounds with CO or its equivalents. In addition, reductive carboxylation of C?S bonds with CO₂ is described.     

非负载型铁催化剂上二氧化碳加氢制低碳烯烃

研究了非负载型铁催化剂上CO₂加氢制低碳烯烃反应.结果显示,添加碱金属可显著提高铁催化剂上的CO₂转化率和烯烃选择性.在经K和Rb修饰的Fe催化剂上,CO₂转化率可达约40%,烯烃选择性达到50%以上,其中C₂~C₄烯烃收率超过10%.催化剂表征结果表明,碱金属促进了催化剂中碳化铁的生成,这可能是催化剂性能提高的一个关键原因.随着K含量由1 wt%增加至5 wt%,CO₂转化率及烯烃选择性均升高.但K含量过高时,催化剂活性降低.这可能是由于催化剂比表面积和CO₂化学吸附量降低所致.当K含量为5%~10%时,K-Fe催化剂上烯烃收率较高; 进一步添加适量的硼可进一步提高烯烃选择性,且CO₂转化率下降不大.     

Dodecacarbonyltriruthenium catalysed carbonylation of amines and hydroamidation of olefins

Dodecacarbonyltriruthenium (Ru₃(CO)₁₂) is an effective homogeneous catalyst precursor for the carbonylation of amines and hydroamidation of olefins under a carbon monoxide pressure of 40 kg cm⁻² at 120–180°C. By the carbonylation of benzylamine, N-benzylformamide was obtained in 77% yield. 1-Octene was hydroamidated with benzylamine to N-benzylnonanamide in 67% yield (the selectivity to its linear isomer was 81%). These reactions appear to include ruthenium carbamoyl complex as the common key intermediate.     

(PCy3)2Cl2RuCHPh Catalyzed Kharasch additions. Application in a formal olefin carbonylation

(PCy₃)₂Cl₂RuCHPh-catalyzed Kharasch additions of trihaloalkanes across olefins provide polyhalogenated adducts, which upon hydrolysis furnish α,β-unsaturated ketones, aldehydes, or γ-hydroxybutenolides. This two-step process represents an overall acylation or carbonylation of an olefin.     

A Convenient Palladium‐Catalyzed Reductive Carbonylation of Aryl Iodides with Dual Role of Formic Acid

Palladium‐catalyzed reductive carbonylation of aryl halides represents a straightforward pathway for the synthesis of aromatic aldehydes. The known reductive carbonylation procedures either require CO gas or complexed compounds as CO sources. In this communication, we developed a palladium‐catalyzed reductive carbonylation of aryl iodides with formic acid as the formyl source. As a convenient, practical, and environmental friendly methodology, no additional silane or H₂ was required. A variety of aromatic aldehydes were isolated in moderate to excellent yields under mild reaction conditions. Notably, this is the first procedure on using formic acid as the formyl source.