Asymmetric Synthesis of Novel Vicinal Amino Alcohols via Intramolecular Ketone-N-sulfinylimine Pinacol-Type Reductive Coupling Promoted by SmI2

A novel intramolecular asymmetric ketone-N-sulfinylimine pinacol-type reductive coupling reaction induced by SmI₂ was reported. A series of 1-amino-1,2,3,4-tetrahydronaphthalen-2-carbinols were obtained in moderate to good yields with excellent ee and high dr.

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AgF-Mediated Homocoupling Reaction of Trialkoxy Aryl Silanes

In this article, we present the direct homocoupling reaction of trialkoxy aryl silanes mediated by AgF in moderate to excellent yields in very mild conditions. It is an important complement for the synthesis of symmetrical biaryls by using homocoupling of trialkoxy silanes. In this reaction, no other catalyst such as Pd or Cu was necessary.

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CuFe2O4 Nanoparticles: A Magnetically Recoverable and Reusable Catalyst for the Synthesis of Coumarins via Pechmann Reaction in Water

The synthesis of coumarins by hydroxyalkylation of phenols with ethyl acetoacetate (via Pechmann reaction) is attempted using magnetically separable and reusable CuFe₂O₄ nanoparticles in water.

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Oxidation of Benzaldehydes to Benzoate Esters Using Household Bleach and Sodium Iodide in Alcohol Solvents

Various substituted benzaldehydes were converted into benzoate esters with household bleach and sodium iodide in an alcohol solvent. The reaction works best with methanol. Only 4-chlorobenzaldehyde, 3-nitrobenzaldehyde, and 4-nitrobenzaldehyde reacted completely with 1-propanol under these conditions.

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Convenient Synthesis of Monobenzylated Hydrazides via Aqueous Zinc-Mediated Addition Reactions

Addition of substituted benzyl bromides to dialkyl azodicarboxylates under aqueous zinc-mediated addition conditions occurs readily to afford monobenzylated hydrazides in good to excellent yields. The reaction is tolerant of a variety of substituents on the benzyl bromide ring. Several dialkyl azodicarboxylates were successfully tested under the reaction conditions. The limitations of the reaction are also addressed.

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Role of Additives in Chiral Amine-Catalyzed Direct Aldol Reaction

A systematic study of chiral adducts derived from amines as catalysts for aldol reaction revealed that enantioselective outcome depends on the chiral enamine intermediate and not the face-selective activation of aldehyde. A simple addition compound of proline and 8-hydroxy quinoline was found to be a good catalyst.

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Solvent-Free Synthesis of Dihydropyridines and Acridinediones via a Salicylic Acid–Catalyzed Hantzsch Multicomponent Reaction

A multicomponent Hantzsch synthesis of 1,4-dihydropyridines and acridinediones from commercially available aldehydes, ammonium acetate, and ethyl acetoacetate or dimedone, in the presence of salicylic acid as an efficient catalyst, in good yield and short reaction time is reported.

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One-Pot,Catalyst-Free Synthesis of Spirooxindole and 4H-Pyran Derivatives

The synthesis of biologically valuable spirooxindoles and 4H-pyrans is described under catalyst-free conditions through sequential Knoevenagel–Michael–cyclization reactions from isatin or aromatic aldehyde, malononitrile, and 1,3-dicarbonyl compounds. The reaction conditions are very simple, providing excellent yield.

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In Situ Demethoxylation,Dechloridation, or Decyanogenation from Coupling Aromatic Compounds Mediated by Potassium Metal

The potassium metal can promote direct arylation of unactivated aromatic C-H bonds under an oxygen atmosphere. Interestingly, in situ demethoxylation, dechloridation, or decyanogenation from the corresponding coupling aromatic compounds mediated by potassium metal was also observed in the radical reaction systems.

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Efficient Deallylation of Allyl Phenyl Ethers by Molecular Iodine in PEG-400 and Their Utility for Flavone Synthesis

Rapid and efficient deallylation of allyl phenyl ethers by molecular iodine (20 mol%) in polyethylene glycol-400 at 60 °C has been reported. This method has short reaction time, readily available catalyst, and reuse of reaction medium with good yield. The utility of this methodology has been extended to flavone synthesis.

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Synthesis of Novel Asymmetrical Single-Chain Phosphoglycol-Based Bolaamphiphiles

The synthesis of long-chain 1,ω-diols with orthogonal cleavable protecting groups can be effectively performed with the use of the Grignard coupling reaction, successfully leading to the preparation of novel asymmetrical single-chain phosphoglycol-based bolaamphiphiles—a side-product that always occurred during the synthesis of symmetrical bolalipids.

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An Expedient Approach for the Synthesis of 1-Alkyl-4-propionylpyrrolidin-2-ones

A simple and useful tandem addition–cyclization reaction of primary amines on a prepared α-functionalized propylvinyl ketone 3 in methanol at reflux is a promising route for the synthesis of a new family of 1-alkyl-4-propionylpyrrolidin-2-ones 4.

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Enantioselectivity Investigation of Short Polar Peptides with Different Positions in the Michael Reaction

This work reports the effectiveness of short polar peptides as asymmetric catalysts in Michael reactions to attain good yields of enantio- and diastereoselective isomers. In a comparison, glutamic acid and histidine produced greater ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric Michael addition reaction in water.

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Lipase-Catalyzed Condensation Reaction of 4-Nitrobenzaldehyde with Acetyl Acetone in Aqueous–Organic Cosolvent Mixtures and in Nearly Anhydrous Media

The nature of the product(s) in lipase-catalyzed reaction of acetyl acetone with 4-nitrobenzaldehyde was found to depend upon the source of lipase and the reaction medium. Mucor javanicus lipase was found to give 70% aldol with 80% enantiomeric excess in anhydrous t-amyl alcohol. A 2:2 adduct was formed by the dimerization of the aldol along with an unsaturated cyclic ether as the side products in varying proportions depending upon the reaction medium and the lipase used.

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K3PO4-KOH Mixture as Efficient Reagent for the Deprotection of 4-Aryl-2-methyl-3-butyn-2-ols to Terminal Acetylenes

A mixture of potassium hydroxide and potassium phosphate was found to be an active reagent mixture for the cleavage of 2-hydroxypropyl-protected acetylenes. The reaction was performed in toluene at reflux temperature and gave terminal acetylenes in good to excellent yields within very short periods of time. Numerous other functional groups are tolerated.

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Efficient One-Pot Synthesis of 3-Amino-7-azaindoles Under Microwave Irradiation

An efficient one-pot synthesis of 3-amino-7-azaindoles was developed, starting from ethyl (3-cyanopyridin-2-yl)carbamate and α -bromoketones by microwave-assisted Thorpe–Ziegler cyclization in the presence of a base. This method features excellent yields, short reaction time (10min), and high functional group compatibility.

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Free Radical–Mediated Chemoselective Reduction of Enones

A novel methodology has been devised for the chemoselective reduction of enones involving the use of ⁿ Bu₃SnH and azobisisobutyronitrile. The 1,4-reduction of variously substituted α,β-unsaturated cyclic and acyclic enones has been successfully carried out under free radical reaction conditions. The reaction has been determined to proceed via single-electron transfer.

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5-Ethoxymethylidene-4-thioxo-2-thiazolidinone as Versatile Building Block for Novel Biorelevant Small Molecules with Thiopyrano[2,3-d][1,3]thiazole Core

5-Ethoxymethylidene-4-thioxo-2-thiazolidinone was studied as versatile core building block in the synthesis of new thiopyrano[2,3-d]thiazole derivatives relevant for medicinal chemistry purposes under hetero-Diels–Alder reaction conditions. Promising compounds (6, 10) were identified among synthesized series with high antitumor and moderate antiviral activity.

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Synthesis and CuAAC Reactions of Azidoalkylethoxysilanes: Grafting CuAAC Products onto Silica Surface

One-pot synthetic protocols of novel azido functionalized silane coupling agents from corresponding terminal mesylated or tosylated 1-olefins were developed. Azido groups were successfully converted to the corresponding 1,2,3-triazol ring by the copper-catalyzed azido alkyne coupling (CuAAC) reaction without alkoxysilane decomposition. The CuAAC product was readily grafted onto the silica surface in good yield.

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Aluminium Chloride–Catalyzed Synthesis of 4-Benzyl Cinnolines from Aryl Hydrazones

An efficient synthesis of 4-benzyl cinnolines from aryl phenylallylidene hydrazone is described. In this report aluminium chloride as a Lewis acid catalyst and toluene as a solvent are used for the synthesis. This method is expected to more advantageous than the other reported methods of synthesis of the cinnoline rings because of its low cost, better yield, and benign reaction conditions.

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