Carbonylation Of Alkynes Research Articles

Palladium-catalyzed aerobic oxidative carbonylation of alkynes with amines: a general access to substituted maleimides.

A catalytic oxidative carbonylation reaction was developed for the synthesis of polysubstituted maleimides from alkynes and amines with air as a green oxidant. This novel transformation proceeds in the presence of palladium chloride without the need for expensive ligands or additives and has a broad substrate scope affording a variety of maleimides in good to high yields.

New type of oscillatory processes—oxidative carbonylation of alkynes in the homogeneous catalysis by Pd complexes. Phenylacetylene

The purpose of this review is to acquaint readers with the main results of concentration oscillation studies in the reaction of phenylacetylene oxidative carbonylation proceeding under the conditions of homogeneous metal complex catalysis. It was shown that the oscillatory regime is realized in the range of concentrations and partial pressures limited by some rigorous frames. Some interesting features of this process were studied. The products of this reaction have been identified.

Markovnikov-Selective Palladium Catalyst for Carbonylation of Alkynes with Heteroarenes.

A new class of palladium catalysts, based on heterocyclic diphosphines, was rationally designed and synthesized. Application of one of these catalysts allows novel Markovnikov-selective carbonylation of non-activated alkynes with heteroarenes to give the corresponding branched α,β-unsaturated ketones in excellent yields (up to 97 %) and regioselectivities (b/l up to 99:1). In addition to heteroarenes, other common nucloephiles (alcohol, phenol, amine, and amide) furnish the desired carbonylation products smoothly in high yields.

Markovnikov‐Selective Palladium Catalyst for Carbonylation of Alkynes with Heteroarenes

AbstractA new class of palladium catalysts, based on heterocyclic diphosphines, was rationally designed and synthesized. Application of one of these catalysts allows novel Markovnikov‐selective carbonylation of non‐activated alkynes with heteroarenes to give the corresponding branched α,β‐unsaturated ketones in excellent yields (up to 97 %) and regioselectivities (b/l up to 99:1). In addition to heteroarenes, other common nucloephiles (alcohol, phenol, amine, and amide) furnish the desired carbonylation products smoothly in high yields.

Iron-Catalyzed Intramolecular Alkyne–Carbonyl Metathesis: A New Cyclization Strategy for the Synthesis of Benzocarbazole and Azepino[1,2-a]indole Derivatives

An efficient synthesis of benzocarbazoles and benzo[3,4]azepino[1,2-a]indole derivatives through an FeCl3-catalyzed alkyne–aldehyde metathesis reaction is described. Structurally diverse benzo[a]carbazoles, benzo[c]carbazoles, and benzo[3,4]azepino[1,2-a]indoles have been achieved in good yields with high regio- and chemoselectivity in the presence of catalytic, inexpensive, and environmentally friendly FeCl3­ as a catalyst.

A Regioselective Approach to Trisubstituted Pyrazoles via Palladium-Catalyzed Oxidative Sonogashira-Carbonylation of Arylhydrazines.

A palladium-catalyzed oxidative carbonylation of arylhydrazines and alkynes with balloon pressure CO/O2 to afford trisubstituted pyrazoles in a one-pot manner has been developed. The formation of trisubstituted pyrazoles involves a sequential C-N bond cleavage, carbonylation, Sonogashira coupling, Michael addition, and intramolecular condensation cyclization tandem process. An unprecedented oxidative Sonogashira-carbonylation reaction of arylhydrazine plays a key role for such a facile approach to pyrazoles.

Altering the Cyclization Modes: Temperature-Dependent Intramolecular 7-Endo-Dig vs 6-Endo-Dig Electrophilic Ring Closures.

In an attempt to construct 10-acyl-5H-benzo[e]pyrrolo[1,2-a]azepines via acid-catalyzed intramolecular alkyne carbonyl metathesis, two distinctive modes of cyclization were revealed to depend on the reaction temperatures. 5H-Benzo[e]pyrrolo[1,2-a]azepine-1-carbaldehydes with a substituent at the C11 position were obtained as major products at 90 °C as a result of intramolecular 7-endo-dig cyclization, while 6-endo-dig ring closure by electrophilic addition of nitrogen of the pyrrole to a vinyl cation generated under acidic medium followed by an unprecedented domino rearrangement process was observed at 40 °C in some cases, resulting in 5-aryl-11H-benzo[d]pyrrolo[1,2-a]azepine-1-carbaldehydes along with the former products.

Polyaromatic heterocycles through intramolecular alkyne carbonyl metathesis: 5-Acylnaphtho[2,1-b]benzofurans

A modular approach to 5-acylated naphtho[2,1-b]benzofurans was developed where Sonogashira cross-coupling and intramolecular alkyne carbonyl metathesis were sequentially employed to build the aromatic benzene C ring of naphtho[2,1-b]benzofuran with an acyl group at the C5 position.

Regiospecific Synthesis of 5- and 6-Acylated Naphtho[1,2-b]benzofurans via Intramolecular Alkyne Carbonyl Metathesis

Straightforward access to various 5- and 6-acylated naphtho[1,2-<i>b</i>]benzofurans was achieved by successive Sonogashira coupling and intramolecular alkyne carbonyl metathesis to assemble the central aromatic C ring of naphtho[1,2-<i>b</i>]benzofurans regiospecifically substituted with an acyl group at the C5 or C6 position.

ChemInform Abstract: Synthesis of 2‐Alkynoates by Palladium(II)‐Catalyzed Oxidative Carbonylation of Terminal Alkynes and Alcohols.

AbstractThe improved protocol uses a novel catalyst system and has a wider substrate scope than previous methods.

High performance of CuY zeolite for catalyzing acetylene carbonylation and the effect of copper valence states on catalyst

Catalytic reactions of acetylene have become a subject of renewed interest. However, recent literatures about the synthesis of acrylic acid by acetylene carbonylation were rare to be found. In our research, the yield of acrylic acid is greatly improved to ∼86% (242.85gAcrylicacid/gCat.·h) by using heterogeneous catalyst Cu(I)Y, against ∼70% from other reports using complex homogeneous catalyst. Y modified with different valence states copper were prepared by heating the precursor at various atmospheres and characterized by XRD, BET, XPS and FT-IR. More than one type of copper (Cu2+, CuO, Cu2O, Cu+ or Cu0) was found on one sample. Moreover, the distribution and the forming process of these types of copper were determined. According to FT-IR using pyridine or CO as probe, Cu+ at site II′ not only enhanced the acid strength obviously, but also promoted the formation of the most stable monocarbonyls. Furthermore, the strong acid site and the stable monocarbonyls are beneficial for the acetylene carbonylation.

ChemInform Abstract: Palladium‐Catalyzed Oxidative N‐Dealkylation/Carbonylation of Tertiary Amines with Alkynes to α,β‐Alkynylamides.

AbstractFor the first time, an effective Pd—C‐catalyzed oxidative N‐dealkylation/carbonylation of various alkynes with aliphatic as well as cyclic tertiary amines is developed.

Cocrystals of 1,4-diethynylbenzene with 1,3-diacetylbenzene and benzene-1,4-dicarbaldehyde exhibiting strong nonconventional alkyne-carbonyl C-H...O hydrogen bonds between the components.

Weak interactions between organic molecules are important in solid-state structures where the sum of the weaker interactions support the overall three-dimensional crystal structure. The sp-C-H...N hydrogen-bonding interaction is strong enough to promote the deliberate cocrystallization of a series of diynes with a series of dipyridines. It is also possible that a similar series of cocrystals could be formed between molecules containing a terminal alkyne and molecules which contain carbonyl O atoms as the potential hydrogen-bond acceptor. I now report the crystal structure of two cocrystals that support this hypothesis. The 1:1 cocrystal of 1,4-diethynylbenzene with 1,3-diacetylbenzene, C10H6·C10H10O2, (1), and the 1:1 cocrystal of 1,4-diethynylbenzene with benzene-1,4-dicarbaldehyde, C10H6·C8H6O2, (2), are presented. In both cocrystals, a strong nonconventional ethynyl-carbonyl sp-C-H...O hydrogen bond is observed between the components. In cocrystal (1), the C-H...O hydrogen-bond angle is 171.8 (16)° and the H...O and C...O hydrogen-bond distances are 2.200 (19) and 3.139 (2) Å, respectively. In cocrystal (2), the C-H...O hydrogen-bond angle is 172.5 (16)° and the H...O and C...O hydrogen-bond distances are 2.25 (2) and 3.203 (2) Å, respectively.

ChemInform Abstract: Palladium‐Catalyzed Regioselective Difluoroalkylation and Carbonylation of Alkynes.

A novel, four-component synthetic strategy to synthesize a series of β-difluoroalkyl unsaturated esters/amides with high regioslectivity is described. This Pd-catalyzed difluoroalkylation and carbonylation reaction can be carried out with simple starting materials. Through this protocol, two new C–C bonds (including one C–CF2 bond) and one C–O(N) bond are constructed simultaneously in a single step. The synthetic utility of this reaction system has been certified by the applicability to a wide scope of alkynes and nucleophiles. Preliminary mechanistic studies suggest that the difluoroalkyl radical pathway is involved in this reaction.

Synthesis of 2-Alkynoates by Palladium(II)-Catalyzed Oxidative Carbonylation of Terminal Alkynes and Alcohols.

A homogeneous PdII catalyst, utilizing a simple and inexpensive amine ligand (TMEDA), allows 2‐alkynoates to be prepared in high yields by an oxidative carbonylation of terminal alkynes and alcohols. The catalyst system overcomes many of the limitations of previous palladium carbonylation catalysts. It has an increased substrate scope, avoids large excesses of alcohol substrate and uses a desirable solvent. The catalyst employs oxygen as the terminal oxidant and can be operated under safer gas mixtures.

Synthesis of cyclic acetals of acetylenic carbonyl compounds

A condensation of α-acetylenic carbonyl compounds and their acyclic acetals with 1,2-diols gave substituted 1,3-dioxacycloalkanes in up to 90% yields. 2,4-Disubstituted 1,3-dioxolanes were formed as mixtures of steric isomers, in which trans-forms predominated according to the B3LYP/6-311+G(2d,p) calculations.

Palladium-Catalyzed Regioselective Difluoroalkylation and Carbonylation of Alkynes.

A novel, four-component synthetic strategy to synthesize a series of β-difluoroalkyl unsaturated esters/amides with high regioslectivity is described. This Pd-catalyzed difluoroalkylation and carbonylation reaction can be carried out with simple starting materials. Through this protocol, two new C-C bonds (including one C-CF2 bond) and one C-O(N) bond are constructed simultaneously in a single step. The synthetic utility of this reaction system has been certified by the applicability to a wide scope of alkynes and nucleophiles. Preliminary mechanistic studies suggest that the difluoroalkyl radical pathway is involved in this reaction.

Acetylene carbonylation over Ni-containing catalysts: role of surface structure and active site distribution

Traditional homogeneous catalyst with heterogeneous Ni catalysts (Ni-ZSM-5, Ni-IM-5 and Ni-MCM-41) for acetylene carbonylation. Using proper parameters to confirm the influence of surface structure and active site distribution on performance.

Dialectics and synergetics in chemistry. Periodic Table and oscillating reactions

This work utilizes examples from chemical sciences to present fundamentals of dialectics and synergetics. The laws of dialectics remain appropriate at the level of atoms, at the level of molecules, at the level of the reactions, and at the level of ideas. The law of the unity and conflict of opposites is seen, for instance, in the relationships between the ionization energy and electron affinity of atoms, between the forward and back reactions, as well as in the differentiation and integration between the various areas of chemistry. The law of the passage of quantitative changes into qualitative changes describes the transformation properties of the compounds when the number and arrangement of atoms in the molecule undergoes changes. According to this law, the development is accompanied by breaks and jumps. This paper suggests equations for the description of these relationships. The law of the negation of the negation is manifested in the Periodic Law, in the evolution of ideas about the mutual transformation of chemical elements, in the development the concept of triads of elements, etc. Small changes in the conventional Periodic Table on the basis of previously rejected versions allow reflecting secondary and additional periodicity. Synergetics, similarly to dialectics, is dedicated to the studies of general laws of evolution. Synergetics includes highly advanced and specified ideas of dialectics. The cornerstone of synergetics is the principles of self-organization and nonlinearity. Mathematical development of these concepts was substantially facilitated by considering oscillating chemical reactions as an example. These reactions are quite complex and therefore provide adequate models for self-organization. Oscillations may exist only upon execution of specific thermodynamic, mathematical, and chemical conditions. Mechanisms of several oscillatory reactions (Belousov–Zhabotinskii, Bray–Liebhavsky, oxidative carbonylation of acetylenes) are briefly reviewed. The construction of novel biomimetic or smart materials based on oscillating reactions is described.

A single-flask synthesis of α-alkylidene and α-benzylidene lactones from ethoxyacetylene, epoxides/oxetanes, and carbonyl compounds

Low temperature treatment of (ethoxyethynyl)lithium with epoxides or oxetanes in the presence of BF3·OEt2, followed by addition of aldehydes or ketones and warming to room temperature, affords structurally diverse five- and six-membered α-alkylidene and α-benzylidene lactones (5) in good to excellent yields. This one-pot process, in which three new carbon–carbon bonds and a ring are formed, affords substituted α,β-unsaturated lactones of predominantly Z-configuration. The reaction likely occurs via alkyne–carbonyl metathesis of a hydroxy–ynol ether intermediate, acid-promoted alkene E- to Z-isomerization, and lactonization.