scholarly journals Palladium Catalyzed α,β-Homodiarylation of Vinyl Esters in Aqueous Medium

2021 ◽  
Author(s):  
Ryszard Ostaszewski ◽  
Damian Trzepizur ◽  
Anna Brodzka ◽  
Dominik Koszelewski ◽  
Monika Wilk
Keyword(s):  
Catalytic Activity ◽  
Functional Group ◽  
Reaction Medium ◽  
Environmentally Benign ◽  
Vinyl Esters ◽  
Arylboronic Acid ◽  
Reaction Conditions ◽  
Mild Conditions ◽  
Palladium Catalyzed ◽  
One Step

Abstract A palladium catalyzed 1,2-diarylation of vinyl esters with sustainable arylbornic acids in water has been developed. This newly elaborated protocol features good functional group tolerance and provides a one-step access to 1,2-diaryletahol derivatives under mild reaction conditions. The presented reaction can be carried out in water smoothly without the addition of any ligands at ambient temperature what makes this procedure environmentally benign. The transformation occurs within a single catalytic cycle and is feasible due to the modification of transition metal catalytic activity through the influence of π-acceptor olefin (benzoquinone) as well as the polar protic reaction medium (water in particular). Moreover, the protocol allows to generate entire compounds libraries (highly profitable in medicinal chemistry) and utilizes sustainable arylboronic acid as coupling partners under mild conditions.

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

scholarly journals Cu(II) and magnetite nanoparticles decorated melamine-functionalized chitosan: A synergistic multifunctional catalyst for sustainable cascade oxidation of benzyl alcohols/Knoevenagel condensation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zahra Alirezvani ◽  
Mohammad G. Dekamin ◽  
Ehsan Valiey
Keyword(s):  
Catalytic Activity ◽  
Knoevenagel Condensation ◽  
Ambient Pressure ◽  
Reaction Medium ◽  
Environmentally Benign ◽  
One Pot ◽  
Benzyl Alcohols ◽  
External Magnet ◽  
Multistep Synthesis ◽  
Multifunctional Catalyst

AbstractThe uniform decoration of Cu(II) species and magnetic nanoparticles on the melamine-functionalized chitosan afforded a new supramolecular biopolymeric nanocomposite (Cs-Pr-Me-Cu(II)-Fe3O4). The morphology, structure, and catalytic activity of the Cs-Pr-Me-Cu(II)-Fe3O4 nanocomposite have been systematically investigated. It was found that Cs-Pr-Me-Cu(II)-Fe3O4 nanocomposite can smoothly promote environmentally benign oxidation of different benzyl alcohol derivatives by tert-butyl hydroperoxide (TBHP) to their corresponding benzaldehydes and subsequent Knoevenagel condensation with malononitrile, as a multifunctional catalyst. Interestingly, Fe3O4 nanoparticles enhance the catalytic activity of Cu(II) species. The corresponding benzylidenemalononitriles were formed in high to excellent yields at ambient pressure and temperature. The heterogeneous Cs-Pr-Me-Cu(II)-Fe3O4 catalyst was also very stable with almost no leaching of the Cu(II) species into the reaction medium and could be easily recovered by an external magnet. The recycled Cs-Pr-Me-Cu(II)-Fe3O4 was reused at least four times with slight loss of its activity. This is a successful example of the combination of chemo- and bio-drived materials catalysis for mimicing biocatalysis as well as sustainable and one pot multistep synthesis.

Palladium-Catalyzed Cyanation under Mild Conditions: A Case Study to Discover Appropriate Substrates among Halides and Pseudohalides

Synlett ◽  
2020 ◽  
Vol 31 (16) ◽  
pp. 1629-1633
Author(s):  
K. Sunil ◽  
Merla Arjuna Rajendra ◽  
Ayyiliath Meleveetil Sajith ◽  
Muthipeedika Nibin Joy ◽  
Vasiliy A. Bakulev ◽  
...  
Keyword(s):  
Environmentally Benign ◽  
Potassium Hexacyanoferrate ◽  
Mild Conditions ◽  
Suitable Substrate ◽  
Wide Range ◽  
Palladium Catalyzed

A case study has been effectively carried out to identify a suitable substrate among halides and pseudohalides for the palladium-catalyzed cyanation reactions under mild conditions. Among the various substrates considered for evaluation, aryl pentafluorobenzenesulfonates and nonaflates were identified to be the best substrates when compared to corresponding halides and pseudohalides. The substoichiometric use of nontoxic, environmentally benign potassium hexacyanoferrate as a cyanide source and exceptionally milder conditions further highlights the significance of the protocol developed. A wide range of electronically biased and sterically challenging substrates provided the corresponding the nitriles in good to excellent yields.

Ionic liquid promoted and mediated green preparation of arylbispyranylmethane and pyran derivatives and their hybrid with a pyrimidine nucleoside

2009 ◽  
Vol 2009 (8) ◽  
pp. 473-477 ◽  
Author(s):  
Xinying Zhang ◽  
Yingying Qu ◽  
Xuesen Fan ◽  
Xia Wang ◽  
Jianji Wang
Keyword(s):  
Ionic Liquid ◽  
High Efficiency ◽  
Reaction Medium ◽  
Environmentally Benign ◽  
Pyrimidine Nucleoside ◽  
Reaction Conditions ◽  
Operation Process ◽  
Antiviral Activities ◽  
Benign Nature ◽  
High Yields

The utilisation of an ionic liquid-[bmim][BF4] as both reaction medium and promoter for the reaction between aldehyde and 4-hydroxy-6-methylpyran-2-one is described. Without any added catalyst, this reaction was realised efficiently to give arylbispyranylmethane derivatives in high yields. Alternatively, when this reaction was carried out in the presence of acetic anhydride, fused pyran derivatives were obtained. These two novel procedures have advantages such as an environmentally benign nature, high efficiency, simple operation process and mild reaction conditions. As an application, these procedures were used in the preparation of novel 5-substituted pyrimidine nucleoside derivatives with potential antiviral activities.

Palladium-catalyzed [4 + 3] dearomatizing cycloaddition reaction of N-iminoquinolinium ylides

2020 ◽  
Vol 7 (18) ◽  
pp. 2612-2617
Author(s):  
Wenhao Dai ◽  
Chunpu Li ◽  
Yichu Liu ◽  
Xu Han ◽  
Xingjun Li ◽  
...  
Keyword(s):  
Functional Group ◽  
Cycloaddition Reaction ◽  
Membered Ring ◽  
Efficient Approach ◽  
Mild Conditions ◽  
Palladium Catalyzed

An efficient approach to obtain saturated seven-membered ring containing three heteroatoms has been developed by using a palladium-catalyzed [4 + 3] dearomatizing cycloaddition. This approach features mild conditions and good functional group tolerance.

scholarly journals Palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides

2017 ◽  
Vol 13 ◽  
pp. 2610-2616 ◽  
Author(s):  
Tao Fan ◽  
Wei-Dong Meng ◽  
Xingang Zhang
Keyword(s):  
Alkyl Radical ◽  
Functional Group ◽  
High Efficiency ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Type Reaction ◽  
Alkyl Bromides ◽  
Reaction Proceeds ◽  
Palladium Catalyzed ◽  
Hydroxy Groups

An efficient palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides has been developed. The reaction proceeds under mild reaction conditions with high efficiency and excellent functional group tolerance, even towards formyl and hydroxy groups. Preliminary mechanistic studies reveal that a secondary trifluoromethylated alkyl radical is involved in the reaction.

One-step Synthesis of β-lactams Using Cyanuric Fluoride

2013 ◽  
Vol 37 (1) ◽  
pp. 25-27 ◽  
Author(s):  
Maaroof Zarei
Keyword(s):  
Reaction Conditions ◽  
One Pot ◽  
Mild Conditions ◽  
One Pot Synthesis ◽  
One Step ◽  
Acetic Acids

Cyanuric fluoride works as an efficient acid activator reagent for the direct [2+2] ketene–imine cycloaddition of substituted acetic acids and imines in a one-pot synthesis under mild conditions. The yields are good to excellent and the reaction conditions are mild, simple and efficient.

Copper(I)-Catalyzed Sulfenylation of 1,3-Dicarbonyl Substrates with Disulfides under Mild Conditions

Synlett ◽  
2019 ◽  
Vol 30 (19) ◽  
pp. 2181-2184 ◽  
Author(s):  
Jingnan Zhao ◽  
Fan Yang ◽  
Zongyi Yu ◽  
Xiaofei Tang ◽  
Yufeng Wu ◽  
...  
Keyword(s):  
Functional Group ◽  
Atom Economy ◽  
Reaction Conditions ◽  
Keto Esters ◽  
Mild Conditions ◽  
Easy Operation

A copper(I) iodine catalyzed sulfenylation of 1,3-dicarbonyl substrates in the presence of MeCN is presented. Various β-keto esters and β-keto amide substrates can react with disulfides to afford their corresponding products in good to excellent yields. The notable features of this protocol include high atom economy, easy operation, mild reaction conditions, and excellent functional group tolerance.

scholarly journals Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids

2019 ◽  
Vol 15 ◽  
pp. 2907-2913 ◽  
Author(s):  
László Orha ◽  
József M Tukacs ◽  
László Kollár ◽  
László T Mika
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Medium ◽  
Cross Coupling ◽  
Environmental Efficiency ◽  
Coupling Reactions ◽  
Sonogashira Coupling ◽  
Mild Conditions ◽  
Palladium Catalyzed ◽  
Alternative Reaction Medium

It was demonstrated that the γ-valerolactone-based ionic liquid, tetrabutylphosphonium 4-ethoxyvalerate as a partially bio-based solvent can be utilized as alternative reaction medium for copper- and auxiliary base-free Pd-catalyzed Sonogashira coupling reactions of aryl iodides and functionalized acetylenes under mild conditions. Twenty-two cross-coupling products were isolated with good to excellent yields (72–99%) and purity (>98%). These results represent an example which proves that biomass-derived safer solvents can be utilized efficiently in common, industrially important transformations exhibiting higher chemical and environmental efficiency.

scholarly journals Palladium-Catalyzed Cross-Coupling of Gem-Bromofluoroalkenes with Alkylboronic Acids for the Synthesis of Alkylated Monofluoroalkenes

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5532
Author(s):  
Laëtitia Chausset-Boissarie ◽  
Nicolas Cheval ◽  
Christian Rolando
Keyword(s):  
Organic Synthesis ◽  
Functional Group ◽  
Materials Science ◽  
Cross Coupling ◽  
High Yield ◽  
Efficient Synthesis ◽  
Mild Conditions ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Novel Strategy

Monofluoroalkenes are versatile fluorinated synthons in organic synthesis, medicinal chemistry and materials science. In light of the importance of alkyl-substituted monofluoroalkenes efficient synthesis of these moieties still represents a synthetic challenge. Herein, we described a mild and efficient methodology to obtain monofluoroalkenes through a stereospecific palladium-catalyzed alkylation of gem-bromofluoroalkenes with primary and strained secondary alkylboronic acids under mild conditions. This novel strategy gives access to a wide range of functionalized tri- and tetrasubstituted monofluoroalkenes in high yield, with good functional group tolerance, independently from the gem-bromofluoroalkenes geometry.

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