DABCO–Bromine Complex: A Novel Oxidizing Agent for Oxidative Deprotection of THP and Silyl Ethers and Semicarbazones to Corresponding Carbonyl Compounds

A tetrameric DABCO–bromine complex was synthesized, characterized, and utilized as a novel active bromine complex for the oxidative deprotection of THP and silyl ethers and semicarbazones to carbonyl compounds.     

Triphenylphosphine–Iodine: An Efficient Reagent System for the Synthesis of Nitriles From Aldoximes

A wide range of aldoximes were smoothly converted to the corresponding nitriles with triphenylphosphine–iodine.     

A Novel Fluorescent Reagent for Analysis of Hydrogen Peroxide

IntroductionTheoxidationofmanyclinicalsubstancesinbodyfluidsproducesaquantityofhydrogenperoxide ,sothedetermina tionoftracehydrogenperoxideisofconsiderableimportanceinclinicalchemistry .1Further,themonitoringofhydrogenperoxideisalsonecessarytoenvironmentalsciencesinceitisakeyspeciesinthereactionsofthetroposphere,beingin volvedinimportantreactionssuchasthecatalyzedoruncat alyzedaqueousphaseoxidationofSO2 andtheultraviolet en hancedaqueousphaseoxidationoforganicspecies.2 Uptonow ,variousmethods…     

Bismuth Chloride–Sodium Nitrite: A Novel Reagent for Chemoselective N-Nitrosation

Bismuth(III) chloride–sodium nitrite was used as a mild and efficient reagent for N-nitrosation of various tetrazoles, secondary amines, and amides under ambient conditions. Nitrosation took place chemoselectively at the nitrogen atom, giving corresponding N-nitroso derivatives in good to excellent yield.     

A New Reagent for the Reduction of Aromatic Nitro Compounds

Reagentsforthereductionofaromaticnitrocompoundstothecorrespondinganilineshavebeensupplementedb}'selenoPheno1'andtransitionmetalhydrides.'ReactionwithtyPicalhydridereagentssuchasLinlffi.'Lotl(OR),H,'andNaBffi4areusuallysluggish.Sodiumselenatedborohydride(NaBH2Se3)andpotaSsiurnselenatedborohydride(KBH2Se3)hadbeenpreparedfromthereactionofsodiumborohydridewithseleniuminglyInebyLalancetteetal5.However,thebehavesasreducerstowardsmanyorganicfunctionalgroupsandtheirapplicationstoorganicsynthes…     

Silica–PSCl3: A Mild and Efficient Reagent for Deoxygenation of Sulfoxides

A new solid supported reagent, silica–PSCl₃, has been developed for deoxygenation of sulfoxides. With this reagent, conversion of sulfoxides to sulfides occurred cleanly and efficiently at room temperature. Facile isolation of the product was achieved by simple filtration of the by‐products without any extensive workup.     

Synthesis of Fused Thioxo-Pyran Systems From α-Methylene Carbonyl Compounds and Bismethylene-1,3-dithietane

A number of [2, 1-b] fused phosphono substituted-thioxo-pyrans 7,10,13 and 18 have been regioselectively synthesised from the reaction of the corresponding α-methylene carbonyl compound with phosphenato-substituted 1,3-dithietane 1. Conversely, 2-thiohydantoin 14 reacts with 1 to afford the respective 4-substituted derivative 15.     

Bromine Complexes of Polyvinylpyrrolidone Supports: A Mild Reagent for the Transformation of α‐Oxoketene Dithioacetals to β‐Oxothiolesters

When α‐oxoketene dithioacetals 1a–n were treated with the bromine complex of a copolymer of 1‐vinyl‐2‐pyrrolidone and 4‐vinylpyridine, the corresponding thiolcarboxylates 2a–n were formed in excellent yields. The reaction also works with other 1‐vinyl‐2‐pyrrolidone‐derived polymers as well as commercially available polyvinylpyrrolidone–bromine complexes. The method is suitable for preparing aliphatic, aromatic, and γ,δ‐unsaturated β‐oxothiolcarboxylates.     

A Novel Reductive Cyclization of o-Nitrobenzamides and Ketones Promoted by Low-valent Titanium Reagent

A short and facile synthesis of a series of 1,2-dihydroquiazolin-4(3H)-ones was accomplished in good yields via novel reductive cyclization of o-nitrobenzamides with ketones promoted by TiCI4/Zn system. The structure was established on the basis of elemental analysis, IR,^1H NMR and confirmed by a single-crystal X-ray diffraction analysis. This method has the advantages of easily accessible starting materials, convenient manipulation and moderate to high yields.     

A Novel Ternary Complex of Europium(Ⅲ) for Eletroluminescent Device

IntroductionSince Tang[1] and Adachi et al.[2 ] reportedtheir double- and triple- layered devices,organicelectroluminescent(EL ) devices have attracted agreat interest due to their efficient emission in thevisible region and their possible application to flatpanel full color display.Among red- emissionorganic materials,europium complexes haveattracted researchers intense attention[3— 10 ]because the sharp emission band of Eu- complexeshas demonstrated the advantage of a very sharp ELemissio…     

Chen's Reagent: A Versatile Reagent for Trifluoromethylation,Difluoromethylenation, and Difluoroalkylation in Organic Synthesis

Methyl fluorosulfonyldifluoroacetate(FSO2CF2CO2Me or MFSDA),often called"Chen's reagent",is commonly used to synthesize trifluoromethylated and difluoroalkylated compounds.This important reagent was initially developed as an efficient trifluoromethylating agent by Professor Qing-Yun Chen and co-workers at Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences in 1989.     

A New Bismuth Nitrate–Catalyzed Electrophilic Substitution of Indoles with Carbonyl Compounds Under Solvent-Free Conditions

An expeditious synthetic method for the preparation of bis(indollyl)methane derivatives has been developed through a bismuth nitrate-catalyzed reaction of indole with various carbonyl compounds in mortar and pastle under solvent-free conditions.     

2,6-Dicarboxypyridinium Fluorochromate–Promoted Oxidation of Alkyl-Arenes into Carbonyl Compounds Under Nonaqueous and Aprotic Conditions

Benzylic C-H oxidation of a wide variety of alkyl- and cycloalkyl arenes employing 2,6-dicarboxypyridinium fluorochromate under mild reaction conditions is described. The corresponding carbonyl compounds are obtained in good to excellent yields.     

Cu−NHC Complex for Chan-Evans-Lam Cross-Coupling Reactions of N-Heterocyclic Compounds and Arylboronic Acids

An efficient copper(II) N-heterocyclic carbene (NHC) complex with an NCN coordination mode was optimized to catalyze the Chan–Evans-Lam (CEL) cross-coupling reaction of imidazole and other N-heterocyclic nucleophiles with arylboronic acid. This air-stable copper catalyst shows robust catalytic performance and tolerates a diverse array of functional groups on both the N-nucleophile and arylboronic acid coupling partners in C−N bond forming reactions with up to 95 % yield. Formation of the Cu−NHC complex in situ generated similar catalytic performance for CEL coupling. Alternative metal ions (Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Zn²⁺, Ru²⁺, and Pd²⁺) were also screened in the presence of the NHC precursor as CEL catalysts.     

Green and Novel Protocol for One-Pot Synthesis of β-Acetamido Carbonyl Compounds Using Mn(bpdo)2Cl2/MCM-41 Catalyst

Aromatic aldehydes were reacted in a one-pot reaction with enolizable ketones, acetonitrile, and acetyl chloride in the presence of Mn(bpdo)₂Cl₂/MCM-41 under reflux condition or at 80 °C to afford the corresponding β-acetamido ketones in good yields.     

Tantalum(V) Chloride–Silica Gel: An Efficient Catalyst for Conversion of Carbonyl Compounds to 1,3‐Oxathiolanes

A variety of carbonyl compounds can be easily converted to the corresponding 1,3‐oxathiolanes in the presence of a catalytic amount of tantalum(V) chloride [TaCl₅] on silica gel in dichloromethane. Mild reaction conditions, efficiency, high yields, operational simplicity, and only 2.5 mol% of TaCl₅ catalyst are some of the major advantages of the procedure.     

Fe-Mediated S–S Bond Cleavage and Its Application in the Synthesis of α-Arylthio Carbonyl Compounds

In the presence of iron dust, diaryl disulfides react with α-bromo carbonyl compounds to obtain α-arylthio carbonyl compounds in good yield at 90 °C under an N₂ atmosphere, using commercial dimethylformamide (DMF) as solvent. The possible reaction mechanism is that the disulfide is reduced by iron dust to give ArSFeSAr and then reacted with α-bromo carbonyl compounds to give product α-arylthio carbonyl compounds and FeBr₂.     

Sodium Percarbonate: A Convenient Reagent for the Thermal and Sonic Oxidative Cleavage of α-Haloketones

Sodium percarbonate has been found to be a mild and effective reagent for the oxidative cleavage of α-haloketones to carboxylic acids. Furthermore, the reactions are dramatically accelerated in the presence of ultrasound with significant enhancement in yields.     

Brønsted Acid–Catalyzed Meyer–Schuster Rearrangement for the Synthesis of α,β-Unsaturated Carbonyl Compounds

An efficient and simple protocol for the Meyer–Schuster rearrangement of propargyl alcohols into α,β-unsaturated carbonyl compounds has been developed using catalytic amounts of p-toluenesulfonic acid in 1,2-dichloroethane.     

CuSO4 · 5H2O: A Novel,Green, Reusable,and Environmentally Friendly Catalyst for the One-Pot,Four-Component Synthesis of β-Acetamido Carbonyl Compounds

Multicomponent reactions for the synthesis of β-acetamido carbonyl compounds have been gained considerable attention in organic synthesis. In this articles, aromatic aldehydes have been employed in a one-pot reaction with enolizable ketones, acetonitrile, benzonitrile, and acetyl chloride in the presence of copper(II) sulfate petahydrate at ambient temperature to afford the corresponding β-acetamido ketones in very good yields. New compounds are reported. The use of readily available copper(II) sulfate petahydrate as a reusable and recyclable catalyst makes this process quite simple, convenient, and environmentally friendly.