An Efficient Catalyst for the Direct Synthesis of N-Phenylpyrrolidine

N-Phenylpyrrolidine is an important N-heterocycle compound used in the fields of medicine, the material chemistry and the synthesis of fine chemicals1-3. There are a lot of methods to produce N-phenylpyrrolidine4-6. However, One of the most promising rout…     

Facile and Efficient One‐Pot Protocol for the Synthesis of Benzoxazole and Benzothiazole Derivatives using Molecular Iodine as Catalyst

Rapid and efficient condensation reactions of 2‐aminothiophenol and 2‐aminophenol with various aldehydes were carried out using I₂ in solvent‐free conditions with or without microwave irradiation to afford the corresponding 2‐substituted benzothiazole and benzoxazole derivatives in good to excellent yields.     

A Modified and Green Procedure for the Synthesis of β-Amido Ketones Using a BrΦnsted-Acidic Ionic Liquid as Novel and Reusable Catalyst

A green and improved method for the synthesis of β‐amido ketones through one‐pot multi‐component reaction of an enolizable ketone, aryl aldehyde, acetonitrile or benzonitrile in the presence of trimethylsilyl chloride using 3‐methyl‐1‐(4‐sulfonic acid)butylimidazolium hydrogen sulfate [(CH₂)₄SO₃HMIM][HSO₄], a Br?nsted‐acidic ionic liquid, as an effective and recyclable catalyst is described. The present methodology offers several advantages such as simple procedure with an easy work‐up, relatively short reaction time, and good to excellent yields.     

High Activity and Selectivity of Cu／SiO2 Catalyst for the Direct Synthesis of Indole

Copper supported over silica exhibited very high activity and selectivity for the direct synthesis of indole at atmospheric pressure. Under the reaction temperature of 325℃,the yield of indole could obtain 88%.     

A New Strategy for the Synthesis of 3-Acyl-coumarin Using Mesoporous Molecular Sieve MCM-41 as a Novel and Efficient Catalyst

3-Acyl-coumarins were obtained in high yields from ortho-hydroxybenzaldehydes and ethyl acetoacetate or ethyl benzoylacetate in acetonitrile in the presence of a catalytic amount of mesoporous molecular sieve MCM-41. 3-Acyl-coumarins were obtained in high yields from ortho-hydroxybenzaldehydes and ethyl acetoacetate or ethyl benzoylacetate in acetonitrile in the presence of a catalytic amount of mesoporous molecular sieve MCM-41.     

Simple and Efficient System for the α-Bromination of a β-Ketoester by Using N-Bromosuccinimide in the Presence of Silica-Supported NaHCO3 as the Heterogeneous Catalyst: An Environmentally Benevolent Approach

Selective and efficient α-bromination of β-ketoesters and cyclic and acyclic ketones is achieved by reaction with N-bromosuccinimide (NBS) catalyzed by silica-supported sodium bicarbonate (NaHCO₃ · SiO₂) under mild reaction conditions and with short reaction times. With 100% selectivity with all substrates, after 45 min at room temperature (20 ± 2 °C), conversions for ethylacetoacetate were 67% and for acetophenone, cyclohexanone, and cycloheptanone were 58, 50, and 55%, respectively. Acetyl acetone recorded 65% conversion with 100% selectivity. Although cyclopentanone and toluene had only 20% conversion, both reactions showed 100% selectivity toward α-bromination. The catalysts exhibit activity and reusability.     

Vanadyl Triflate as an Efficient and Recyclable Catalyst for the Synthesis of α‐Aminonitriles

Abstract

Vanadyl triflate to catalyzed Strecker‐type reactions were successfully carried out by simply mixing aldehydes, amines, and trimethylsilyl cyanide at room temperature to afford α‐aminonitriles in good yields.     

Synthesis of New β-Acetamido Carbonyl Derivatives Using Cellulose Sulfuric Acid as an Efficient Catalyst

New β-acetamido ketone derivatives are synthesized through a one-pot, four-component reaction of benzaldehyde, dimedone, acetyl chloride, and acetonitrile in the presence of cellulose sulfuric acid as an efficient reusable catalyst. The procedure offers advantages in terms of good yields, short reaction times, mild reaction conditions, and reusability of the catalyst.     

New Synthesis of β-Anilinochalcones by Regioselective Oxidation of β-Anilinodihydrochalcones Using Iodine–DMSO

β-Anilinodihydrochalcones readily undergo oxidation α to the carbonyl group region in the presence of a catalytic amount of iodine in dimethyl sulfoxide at 130 °C in good yield. Oxidation of allyloxy-substituted β-anilinodihydrochalcones to β-anilinochalcones is a preferred reaction over deallylation.     

(NH4)3PW12O40 as an Efficient and Reusable Catalyst for the Synthesis and Deprotection of 1,1‐Diacetates

An efficient method for the synthesis of 1,1‐diacetates (acylals) from different aldehydes in the presence of (NH₄)₃PW₁₂O₄₀ and acetic anhydride under solvent‐free conditions at ambient temperature is achieved. Selective conversion of aldehydes was observed in the presence of ketones. The deprotection of acylals has also been achieved using (NH₄)₃PW₁₂O₄₀ in methanol. The catalyst was found to possess good activity and considerable level of reusability.     

Versatile Approach for the Asymmetric Synthesis of (R)‐ and (S)‐Massoialactones

A general synthetic approach to both enantiomers, (R)‐ and (S)‐massoialactones, has been devised from commercially available (S)‐butane‐1,2,4‐triol.     

B2O3/Al2O3 as an Efficient and Recyclable Catalyst for the Synthesis of β-Amino Alcohols under Solvent-Free Conditions

A convenient and efficient procedure for the solvent-free synthesis of β-amino alcohols has been achieved via B₂O₃/Al₂O₃-promoted highly regioselective ring opening of epoxides with aromatic amines in good to excellent yields at room temperature. Additionally, the catalyst can be recycled without affecting the catalytic property.     

Efficient Synthesis of Some New 2,3-Dimethylquinoxaline-1-oxides Using Bis(acetoxy)phenyl-λ 3-iodane as an Oxidant

A series of 2-(arylimino)-3-(hydroxyimino)butanes 3a–g, easily accessed by the condensation of variously substituted anilines 1a–g with biacetyl monoxime 2, were efficiently cyclized to afford 2,3-dimethylquinoxaline-1-oxides 4a–g using bis(acetoxy)phenyl-λ ³-iodane as an oxidant. This methodology utilizes a commercially available and environmental benign oxidant to achieve the title compounds in excellent yields under mild conditions.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

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.     

Aza-Michael Addition of Amines to α,β-Unsaturated Compounds Using Molecular Iodine as Catalyst

Aza-Michael adducts are obtained in very good yields by the conjugate addition of aliphatic amines to α,β-unsaturated compounds using molecular iodine as catalyst in dichloromethane at room temperature. Aromatic amines were found to be reactive under reflux in toluene.     

A Simple Method for Synthesis of Methylene Dioximes Using Poly(ethylene glycol)‐400 as a Phase Transfer Catalyst

Abstract

A simple method for synthesis of methylene dioximes by reaction of ketoximes with dichloromethane in the presence of aqueous sodium hydroxide solution using poly (ethylene glycol)‐400 (PEG‐400) as a phase transfer catalyst is described.     

Dehydrocoupling Polymerization: Poly(silylether) Synthesis by Using an Iron β-Diketiminate Catalyst

We describe the iron-catalyzed polymerizations of diol and silane monomers to obtain fourteen different poly(silylether) products with number average molecular weights (M_n) up to 36.3 kDa. The polymerization reactions developed in this study are operationally simple and applicable to 1° and 2° silane monomer substrates and a range of benzylic and aliphatic diol substrates as well as one polyol example. The polymers were characterized by IR spectroscopy, DSC and TGA and, where solubility allowed, ¹H, ¹³C{¹H}, ²⁹Si{¹H} NMR spectroscopies, GPC and MALDI-TOF were also employed. The materials obtained displayed low T_g values (−70.6 to 19.1 °C) and were stable upon heating up to T_–5%,Ar 421.6 °C. A trend in T_–5%,Ar was observed whereby use of a 2° silane leads to higher T_–5%,Ar compared to those obtained using a 1° silane. Reaction monitoring was undertaken by in situ gas evolution studies coupled with GPC analysis to follow the progression of chain-length growth which confirmed a condensation polymerization-type mechanism.     

Efficient Synthesis of Homoallylic Alcohols/Amines from Allyltributylstannane and Carbonyl Compounds/Imines Using Iodine as Catalyst Under Acetic Acid–Water Medium

This paper describes a general method for the synthesis of homoallylic alcohols and amines by nucleophilic addition reaction of allyltributylstannane to carbonyl compounds and aldimines where iodine acts as a catalyst in H₂O/acetic acid (1:1) medium. Only 10 mol% of I₂ is required for various organic transformations. By using this process, various homoallylic alcohols and amines are produced in good to excellent yields.     

One-Pot Synthesis of 3,4-Dihydropyrimidine-2-(1H)-ones Using CsF–Celite as Catalyst

A facile, efficient, and environmentally benign procedure for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones via the cyclocondensation reaction of aromatic aldehyde, ethyl acetoaceate, and urea catalyzed by CsF–Celite was developed. This environmentally friendly method is superior to previous methods with respect to reaction time, yield, and workup.     

Iodine Supported on 3-Aminopropyl Silica Gel as Efficient Catalyst for Acetylation of Alcohols under Solvent-free Conditions

3-Aminopropyl silica gel (I2/APSG) was found to catalyze the acetylation of alcohols and phenols efficiently with acetic anhydride. The reaction is mild and selective with high yields. A wide variety of alcohols and phenols are selectively converted into the corresponding acetates using I2/APSG under solvent-free conditions at room temperature.