N,N ′-Diiodo-N,N′-1,2-ethanediylbis(p-toluenesulfonamide) as an Efficient Catalyst for Acetylation of Alcohols,Phenols, Amines,and Thiols Under Solvent-Free Conditions

N,N′-Diiodo-N,N′-1,2-ethanediylbis(p-toluenesulfonamide) (NIBTS) is a highly efficient catalyst for the acetylation of alcohols, phenols, amines, and thiols under solvent-free conditions. Primary, secondary, tertiary alcohols; phenols; amines; and thiols can be easily acetylated in good to excellent yields at 80 °C.     

γ‐PCC and γ‐PCC‐SiO2 as Efficient Reagents for Oxidation of Thiols to Disulfides

Abstract

Oxidative coupling of thiols to the corresponding symmetrical disulfides was performed in the presence of γ‐picolinium chlorochromate and its silica gel supported. The reactivity of silica gel supported γ‐picolinium chlorochromate for thiophenol derivatives is more than the reactivity of pyridinium and γ‐picolinium chlorochromates.     

N‐Methylpyrolidin‐2‐one Hydrotribromide (MPHT) as a New and Efficient Reagent for the Oxidation of Sulfides to Sulfoxides and Sulfones

The stable and crystalline N‐methylpyrolidin‐2‐one hydrotribromide (MPHT) effects oxidation of various sulfides to sulfoxides and sulfones.     

Simple,Extremely Fast,and High‐Yielding Oxidation of Thiols to Disulfides

Abstract

Results of oxidation of thiols to disulfides with 1,3‐dibromo‐5,5‐dimethylhydantoin (DBDMH) are described. A simple addition of 0.20–0.25 mol equivalent of solid DBDMH to thiol in chloroform at room temperature yielded the disulfides in excellent yield. The reaction is extremely fast and gave no other oxidized side products.     

(NH4)6Mo7O24·4H2O as an Efficient,Selective, and Reusable Catalyst for the Oxidation of Thiols to Disulfides Using Potassium Bromate

Abstract

Ammonium molybdate, (NH₄)₆Mo₇O₂₄·4H₂O, is found to be an efficient and selective catalyst for the oxidation of thiols to corresponding disulfides using potassium bromate in aqueous acetonitrile as the solvent. Among various solvents tested, CH₃CN/H₂O showed better results in terms of the reaction yield and rate. In the absence of (NH₄)₆Mo₇O₂₄·4H₂O, the oxidation reaction is not selective for the formation of disulfides. The catalyst can be easily recovered after completion of the reaction and reused without any significant loss of its activity.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures.]     

N,N′-Oxalyl-Di-Imidazolide - A New Reagent for the Synthesis of Symmetrical Organic Oxalates

As part of our program to investigate the behavior of pentadianyl radicals, we wished co prepare bis(δ^1,1′ -dicyclohexenyl carbinyl) oxalate (I) and study Its thermal decomposition. Application of the usual methods of oxalate synthesis toward the preparation of I resulted in low or zero yields, those methods involve reaction conditions whereby an acid is used directly in the reaction¹ or is generated during the reaction as a by product². Since we have found I to be sensitive to even trace amounts of acids³, we sought to develop an alternate approach to oxalate synthesis that would avoid adds at all stages.     

The Facile Oxidation of Thiols to Disulfides with Bis(2,2′-Bipyridyl) Copper-(II) Permanganate

The title compound is used in the oxidation of several thiols to produce their corresponding disulfides in excellent yields in methylene chloride at room temperature.     

Triton B–Mediated Mild,Convenient, and Efficient Method for the Selective Alkylation of Cyclic Secondary Amines and Thiols

Alkylation of cyclic secondary amines, thiols, and pyridazinones has been demonstrated with alkyl halides using Triton B as base and reaction medium.     

Silica‐Supported bis (Trimethylsilyl) Chromate: Oxidation of Thiols to Their Corresponding Disulfides

An efficient and convenient method for the oxidation of thiols mediated by silica‐supported bis (trimethylsilyl) chromate (BTSC) in acetonitrile is reported.     

N‐Bromosuccinimide: A Facile Reagent for the Oxidation of Benzylic Alcohols to Aldehydes

The oxidation of benzylic alcohols to aldehydes using N‐bromosuccinimide (NBS) under ambient conditions without use of a transition‐metal catalyst has been described.     

Synthesis,characterization and application of nano-N,N,N′,N′-tetramethyl-N-(silica-n-propyl)-N′-sulfo-ethane-1,2-diaminium chloride as a highly efficient catalyst for the preparation of N,N′-alkylidene bisamides

Research on Chemical Intermediates - A novel mesoporous nanomaterial, namely nano-N,N,N′,N′-tetramethyl-N-(silica-n-propyl)-N′-sulfo-ethane-1,2-diaminium chloride...     

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.     

A New and Efficient Method for the Synthesis of 2,2′-Dibromo-1,1′-binaphthyl Under Microwave Irradiation

Abstract

A very simple and efficient method to prepare 2,2′-dibromo-1,1′-binaphthyl via two-step procedure from β-naphthol in good yield under microwave irradiation is described.     

Cu(NO3)2 · 3 H2O as an Efficient Reagent for the Chemoselective Trimethylsilylation of Primary Alcohols and Oxidation of Trimethylsilyl Ethers

Abstract

Cu(NO₃)₂ · 3 H₂O can be used as an efficient reagent for the chemoselective trimethylsilylation of primary benzylic and aliphatic alcohols with hexamethyldisilazane (HMDS). This reagent is also able to oxidize the obtained trimethylsilyl ethers to the corresponding carbonyl compounds in the presence of wet SiO₂ and KBr. In this study, all reactions are performed in the absence of a solvent and good-to-high yields are obtained.     

O-(2-Aminobenoyl)-Hydroxylamine—A New Reagent for the Direct Conversion of Audehydes to Nitriles

Refluxing an ethanolic solution of O-(2-aminobenzoyl) -hydroxylamine (1) aldenydes and BF₃-Et₂ yields (78–94%) the corresponding nitriles.     

Cerium(III) Chloride: A Highly Efficient Reagent for the Synthesis of α‐Aminonitriles

We report a highly efficient, one‐pot, three‐component condensation of carbonyl compounds, amines, and TMSCN in MeCN; the reaction is significantly promoted by the catalytic amount of cerium(III) chloride at ambient temperature in excellent yields without any adverse effect on the other substituents. The method afforded an elegant alternative to the synthesis of α‐aminonitriles. The reactions are fast and clean, and the products obtained are of high purity.     

N′N′N pincer and N′N bidentate(pyrazolylpyridyl) Rh(I) complexes as catalyst precursors for hydroformylation of olefins

Transition Metal Chemistry - The industrial process of hydroformylation or the oxo process has been used for many years in the production of aldehydes from alkenes. Different metals have been used...     

A New Method for the Synthesis of Selenium Nanoparticles and the Application to Construction of H202 Biosensor

The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive abilityand biocompatibility were successfully synthesized by using the template of chitosan cross-linkedwith glutaradehyde. The resulting selenium nanoparticles were used as a new carrier forhorseradish peroxidase to construct H2O2 biosensors with good performances.     

Silphox [POCl3−n (SiO2) n ] as a New,Efficient, and Heterogeneous Reagent for the Synthesis of Benzimidazole Derivatives Under Microwave Irradiation

Silphox [POCl_3-n(SiO₂)_n] efficiently catalyzes the condensation of benzene-1,2-diamine with mono and dicarboxylic acids under microwave irradiation to afford benzimidazole derivatives in high yields and short reaction times.     

Poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide) and N,N,N′,N′- tetrabromobenzene-1,3-disulfonamide as effective catalysts for conversion of aldehydes to 1,1-diacetates and acetals

Poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide) [PBBS] and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] are effective catalysts for easy preparation of 1,1-diacetates from aldehydes and acetic anhydride, and for easy preparation of acetals using diols under microwave irradiation in the presence of SiO₂.