Catalytic Carbonylation Research Articles

Carbonylation of functionalized diamine diols to cyclic ureas: application to derivatives of DMP 450

Synthesis of the cyclic urea core structure of the HIV protease inhibitor DMP 450 has been achieved via W(CO) 6/I 2-catalyzed carbonylation of diamine intermediates. Carbonylations of related functionalized diamines to derivatives of the DMP 450 core structure were also examined. Selected diamine diol substrates could be converted to the cyclic urea core structure by catalytic carbonylation without protection of the diol functionality.

Cross-linked polymer supported palladium catalyzed carbonylative Sonogashira coupling reaction in water

A cross-linked polymer-supported ionic liquid immobilized palladium catalyst, which is prepared by reaction of the Pd(OAc)2 with copolymer of 3-butyl-1-vinylimidazolium iodide and divinylbenzene, was well characterized and employed as an effective heterogeneous catalyst for carbonylative Sonogashira coupling reaction of aryl iodides with terminal alkynes in water, affording the corresponding α,β-alkynyl ketones in good to excellent yields. The catalytic system not only solves the basic problem of homogeneous palladium catalyst recovery and reuse but also avoids the use of toxic phosphine ligands. The stability of supported palladium was also discussed.

Synthesis, reactivities and catalytic carbonylation of rhodium(I) carbonyl complexes containing isomeric acetylpyridine ligands

[Rh(CO) 2Cl] 2 reacts with two mole equivalent of 2-acetylpyridine ( a), 3-acetylpyridine ( b) and 4-acetylpyridine ( c) to afford chelate [Rh(CO)Cl(η 2-N∩O)] ( 1a) and non-chelate [Rh(CO) 2Cl(η 1-N∼O)] ( 1b, 1c) complexes, where, N∩O = a, N∼O = b, c. Oxidative addition ( OA) of 1a– 1c with CH 3I and C 2H 5I yields penta coordinate rhodium(III) complexes, [Rh(COR)ClI(η 2-N∩O)] {R = –CH 3 ( 2a); –C 2H 5 ( 3a)} and [Rh(COR)(CO)ClI(η 1-N∼O)] {R = –CH 3 ( 2b, 2c); –C 2H 5 ( 3b, 3c)}. Kinetic study for the reaction of 1a– 1c with CH 3I indicates a pseudo-first order reaction. The catalytic activity of 1a– 1c for the carbonylation of methanol to acetic acid and its ester was evaluated at different initial CO pressures 5, 10 and 20 bar at ∼25 °C and higher turn over numbers ( TON = 1581–1654) were obtained compared to commercial Monsanto’s species [Rh(CO) 2I 2] − ( TON = 1000) under the reaction conditions: temperature = 130 ± 1 °C, pressure = 15–32 bar, rpm = 450, time = 1 h and catalyst: substrate = 1: 1900.

Catalytic activity of PdCl 2 complexes with pyridines in nitrobenzene carbonylation

Synthesis of square planar palladium(II) complexes of general structure PdCl 2(X n Py) 2 (where: Py = pyridine; X n Py = 2-MePy; 3-MePy; 4-MePy; 2,4-Me 2Py; 2,6-Me 2Py; 2-ClPy; 3-ClPy and 3,5-Cl 2Py) has been performed in order to study activity of these complexes as catalysts of nitrobenzene (NB) carbonylation – a process of industrial importance leading to production of ethyl N-phenylcarbamate (EPC). Electron withdrawing/electron donating properties of X n Py ligands (described by experimentally determined acidity parameter p K a) have been correlated with activities of PdCl 2(X n Py) 2 complexes during NB carbonylation in presence of catalytic system PdCl 2(X n Py) 2/Fe/I 2/X n Py. We observed that conversions of substrates and yields of EPC increase within increasing basicity of X n Py ligand (for not sterically hindered X n Py's). On the basis of current work and our previous studies a detailed mechanism of catalytic carbonylation of NB is proposed.

First metal complexes of 6,6′-dihydroxy-2,2′-bipyridine: from molecular wires to applications in carbonylation catalysis

The first square planar rhodium(I) complexes containing the 6,6'-dihydroxy-2,2'-bipyridine ligand have been prepared. The complexes form molecular wires in the solid state and are active catalysts for the carbonylation of methyl acetate.

Carbonylation of styrenes catalyzed by bioxazoline Pd(ii) complexes: mechanism of enantioselectivity

Preliminary studies of the elementary steps involved in the reaction of a chiral methyl carbonyl bioxazoline Pd(II) complex with aromatic olefins and CO have allowed development of a new enantioselective catalytic carbonylation process, leading to γ-ketoester derivatives with high yield and good enantiomeric excess. The intermediate palladacycle complexes have been isolated and characterized by NMR spectroscopy and X-ray diffraction. Factors that govern the stereoselectivity of the olefin carbonylation process are discussed.

Preparation of benzolactams by Pd(ii)-catalyzed carbonylation of N-unprotected arylethylamines

An unprecedented NH(2)-directed Pd(II)-catalytic carbonylation of quaternary aromatic α-amino esters to yield 6-membered benzolactams has been developed. The reaction shows a strong bias to 6-membered lactams over 5-membered ones. The steric hindrance around the amino group seems to be pivotal for the success of the process.

ChemInform Abstract: Organometallic Catalysis: From Concepts to Selected Applications

AbstractReview: 40 refs.

ChemInform Abstract: High‐Yielding Synthesis of Weinreb Amides via Homogeneous Catalytic Carbonylation of Iodoalkenes and Iodoarenes.

AbstractPhosphine/palladium ratio has to be 2/1 since one equivalent of phosphine acts as a reductant of Pd(II) to Pd(0) and the other one is coordinating.

Rhodium(I) carbonyl complexes of quinoline carboxaldehyde ligands and their catalytic carbonylation reaction

The dimeric rhodium precursor [Rh(CO) 2Cl] 2 reacts with quinoline ( a) and its three isomeric carboxaldehyde ligands [quinoline-2-carboxaldehyde ( b), quinoline-3-carboxaldehyde ( c), and quinoline-4-carboxaldehyde ( d)] in 1:2 mole ratio to afford complexes of the type cis-[Rh(CO) 2Cl(L)] ( 1a– 1d), where L = a– d. The complexes 1a– 1d have been characterised by elemental analyses, mass spectrometry, IR and NMR ( 1H, 13C) spectroscopy together with a single crystal X-ray structure determination of 1c. The X-ray crystal structure of 1c reveals square planar geometry with a weak intermolecular pseudo dimeric structure (Rh⋯Rh = 3.573 Å). 1a– 1d undergo oxidative addition ( OA) with different electrophiles such as CH 3I, C 2H 5I and I 2 to give Rh(III) complexes of the type [Rh(CO)(COR)Cl(L)I] {R = –CH 3 ( 2a– 2d), R = –C 2H 5 ( 3a– 3d)} and [Rh(CO)Cl(L)I 2] ( 4a– 4d) respectively. 1b exhibits facile reactivity with different electrophiles at room temperature (25 °C), while 1a, 1c and 1d show very slow reactivity under similar condition, however, significant reactivity was observed at a temperature ∼40 °C. The complexes 1a– 1d show higher catalytic activity for carbonylation of methanol to acetic acid and methyl acetate [Turn Over Frequency (TOF) = 1551–1735 h −1] compared to that of the well known Monsanto’s species [Rh(CO) 2I 2] − (TOF = 1000 h −1) under the reaction conditions: temperature 130 ± 2 °C, pressure 33 ± 2 bar, 450 rpm and time 1 h. The organometallic residue of 1a– 1d was also isolated after the catalytic reaction and found to be active for further run without significant loss of activity.

ChemInform Abstract: Advances in Catalytic Carbonylation with Transition Metal Complexes in Homogeneous Phase

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: C2+ Carboxylic Acids by Catalytic Carbonylation of Methanol with Rhodium.

ChemInform Abstract: C2+ Carboxylic Acids by Catalytic Carbonylation of Methanol with Rhodium.

ChemInform Abstract: Homogeneous Catalytic Carbonylation of Nitroaromatics. Part 4. Preparation and Characterization of Ruthenium Radical Cations.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Catalytic Carbonylations of Nitrogen-Containing Organic Compounds

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Oxidative carbonylation of glycerol to glycerol carbonate catalyzed by PdCl 2(phen)/KI

We present a direct and highly efficient approach for synthesizing glycerol carbonate, via the catalytic oxidative carbonylation of glycerol, using PdCl 2(phen) (phen = 1,10-phenanthroline) as catalyst with the aid of KI. The palladium catalyst loading as low as 0.25 mol% is sufficient for high conversion (92%) and selectivity (99%) at the reaction condition: 2.0 MPa CO, 1.0 MPa O 2, 140 °C, 2 h. The turnover frequency (TOF) reaches 184 h −1. Furthermore, using crude glycerol, we achieved 85% conversion of glycerol. We discuss in detail a plausible mechanism based on PdI 2(phen) as an intermediate. We propose that there is synergistic effect of I − and 1,10-phenanthroline on the performance of the Pd complex catalyst. Based on the cyclic voltammograms, the reduction of PdI 2(phen) occurred at a more positive potential than that of PdCl 2(phen). This may explain why the catalytic activity of PdI 2(phen) was more effective than that of PdCl 2(phen).

Triphenylphosphane-Modified Cobalt Catalysts for the Selective Carbonylation of Ethyl Diazoacetate

The triphenylphosphane-substituted carbonyl cobalt complexes Co2(CO)7(PPh3), Co2(CO)6(CHCO2Et)(PPh3), and [Co(CO)3(PPh3)2][Co(CO)4] were found to be more effective precatalysts in the carbonylation of ethyl diazoacetate under atmospheric pressure of carbon monoxide at 10 °C in dichloromethane solution than the parent Co2(CO)8 and Co2(CO)7(CHCO2Et) complexes. The highly reactive (ethoxycarbonyl)ketene is the primary product of the catalytic carbonylation, which dimerizes in the absence of a proper scavenger. In the presence of ethanol as the trapping reagent diethyl malonate is the final product of the carbonylation reaction. The formation of (ethoxycarbonyl)ketene using the catalyst precursor Co2(CO)7(PPh3) occurs in a catalytic cycle, where Co2(CO)6(PPh3) and Co2(CO)6(CHCO2Et)(PPh3) are the repeating species. The 16e species Co2(CO)6(PPh3) is involved in the deazotization of ethyl diazoacetate, and Co2(CO)6(CHCO2Et)(PPh3) leads to the (ethoxycarbonyl)ketene formation. In the absence of carbon monoxide or at low CO concentration the reaction of Co2(CO)6(CHCO2Et)(PPh3) with ethyl diazoacetate is the source of Co2(CO)5(CHCO2Et)2(PPh3), which is not an active catalyst for the carbonylation of ethyl diazoacetate. Using [Co(CO)3(PPh3)2][Co(CO)4] as the catalyst precursor, the intermediary formation of [Co(CO)3(PPh3)2][Co(CO)3(O═C═CHCO2Et)] through radical pairs is assumed. Substituting PPh3 in Co2(CO)7(PPh3), Co2(CO)6(CHCO2Et)(PPh3), and [Co(CO)3(PPh3)2][Co(CO)4] by polymer-bound PPh3 results in active and reusable catalysts for the selective carbonylation of ethyl diazoacetate in dichloromethane solution at 40 °C and 11 bar of pressure with up to 5.1 mol of product/((mol of catalyst) h) turnover frequency.

ChemInform Abstract: Palladium(I) Carbonyl Cation Catalyzed Carbonylation of Olefins and Alcohols in Concentrated Sulfuric Acid.

A new palladium catalyst was found to exhibit high catalytic activity for carbonylation of olefins and alcohols. cyclo-Bis(μ-carbonyl)dipalladium(I) cation (1) with bridging CO ligands is formed by reductive carbonylation of palladium sulfate, PdSO4, in concentrated H2SO4. When an olefin or alcohol is added, complex 1 changes to a new complex (2) with terminal CO ligands, and tertiary carboxylic acids are obtained in high yields at room temperature and atmospheric pressure of CO. IR and 13C NMR studies suggest that complex 2 may be tentatively formulated to be [Pd2(CO)2]2+, in which the terminal CO ligands are chemically equivalent. Complex 1 is a catalyst precursor, and complex 2 functions as an active species for the carbonylation of olefins and alcohols. The catalytic behavior of the palladium carbonyl catalyst supports the recently proposed reaction mechanism involving an olefin−metal−CO complex as an intermediate for the catalytic carbonylation of olefins and alcohols in strongly acidic solution.

Catalytic carbonylation in ionic liquids

Synthesis gas, which is formed upon the gasification of solid fossil fuels, is a source of carbon monoxide—a valuable reagent for chemical industry. In this review, studies performed in the last few years at the Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, on the catalytic carbonylation of olefins, alcohols, and halides in ionic liquids are considered. Catalytic systems containing no phosphine ligands were developed; these systems make it possible to recycle the homogeneous catalyst by the extraction of synthetic products from the reaction mass.

High-yielding synthesis of Weinreb amides via homogeneous catalytic carbonylation of iodoalkenes and iodoarenes

Iodoarenes (iodobenzene and 2-iodothiophene) and iodoalkenes (1-iodocyclohexene, 1-iodo-4- tert-butylcyclohexene, 1-iodo-2-methylcyclohexene and 1-iodo-1-(1-naphthyl)ethene) were used as substrates in palladium-catalysed aminocarbonylation with N, O-dimethylhydroxylamine. The corresponding Weinreb amides were prepared in high isolated yields (up to 87%) when forcing conditions (40–60 bar of CO, 50 °C) were used. The aminocarbonylation provides the Weinreb amides as pure products in a chemoselective reaction. No formation of ketocarboxamides, due to double CO insertion, except for 2-iodothiophene, was observed even at 60 bar of CO pressure.

Substrate structure governs maximum rate of catalysis exerted by cyclodextrin oxidase chemzymes

Selectively modified α- and β-cyclodextrin ketones or aldehydes act as artificial oxidases on a variety of small lipophilic substrates. The structure of the substrate is a highly important factor governing how effectively the oxidation reaction can be catalyzed. Amino acid-type substrates were not prone to catalysis, which yields new information about the limits of CD catalysis. Aniline showed some non-quantifiable catalysis, but for quinones and benzyl alcohols no net catalysis was detected. For aminophenol oxidation, o-aminophenols are far better substrates than p-aminophenols. The CD-catalyzed reaction follows Michaelis–Menten kinetics, involves CD cavity binding of the substrate and substrate recognition, and thus encompasses many of the hallmarks of natural enzymatic catalysis. Strong binding of the cooxidant H2O2 to the CD catalytic carbonyl group is a prerequisite for the subsequent oxidation of the substrate and in accordance with this, the binding of H2O2 to β-CD dialdehyde was shown to be strong (K d = 1.4 mM). β-CD 6A,6D-diketone which binds H2O2 weaker than an aldehyde was accordingly a less efficient oxidase. The wide range of substrates applicable to CD chemzyme catalysis brings about optimism for future scopes of synthetic biology.