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.     

p-Toluenesulfonyl chloride as a new and effective catalyst for acetylation and formylation of hydroxyl compounds under mild conditions

<正>The catalytic application of p-toluenesulfonyl chloride for efficient acetylation of various types of alcohols and phenols with acetic anhydride in solvent-free conditions is reported.Also structurally diverse alcohols were formylated using formic acid based on the use of catalytic amount of p-toluenesulfonyl chloride under solvent-free condition.The reactions were carried out in short reaction time and in good to excellent yields at room temperature.     

H14[NaP5W29MoO110]: a Novel and Useful Catalyst for Aminolysis of Epoxides with Amines under Solvent-Free Conditions

A simple and efficient method has been developed for the synthesis of β-amino alcohols by ring opening of epoxides in the presence of a catalytic amount of H14[NaP5W29MoO110] at room temperature under solvent-free conditions. The reaction works well for both aromatic and aliphatic amines.     

Poly(diallyldimethylammonium chloride) as an Efficient Phase Transfer Catalyst in Solvent‐Free Reduction of Carbonyl Compounds with NaBH4

Poly(diallyldimethylammonium chloride) resin was used as an efficient polymeric phase transfer catalyst, which catalyzed the chemoselective reduction of aldehydes and ketones by NaBH₄ to give the corresponding alcohols in high yields under solvent-free conditions.     

Strontium chloride-catalyzed one-pot synthesis of 4(3H)- quinazolinones under solvent-free conditions

<正>Strontium chloride was used as an efficient and recyclable catalyst in one-pot condensation of anthranilic acid,ortho esters and amines leading to the formation of 4(3H)-quinazolinone derivatives in good yields at room temperature under solvent-free conditions.     

Polyvinylpolypyrrolidonium tribromide as new and metal-free catalyst for the formylation and trimethylsilylation of hydroxyl group

Trimethylsilylation of alcohols was achieved using 1,1,1,3,3,3-hexamethyldisilazane(HMDS) as silylating agent,in the presence of polyvinylpolypyrrolidonium tribromide in acetonitrile at room temperature.Also a variety of alcohols were converted into alkyl formates by ethyl formate and a catalytic amount of polyvinylpolypyrrolidonium tribromide under solvent free conditions at room temperature.     

Selective monotetrahydropyranylation of symmetrical diols using P_20_5/Si0_2 under solvent-free conditions and their depyranylation

Selective protection of one of the hydroxyl group in 1,n-symmetrical diols is achieved by P_2O_2/SiO_2-catalyzed reaction of the diol with dihydropyran under solvent-free conditions at room temperature.This selective protection is simple and it occurred under economically cheap conditions in high yield.The deprotected diol is simply obtained by refluxing of this compound in methanol using the same catalyst without any byproduct formation or additional purifications.     

A novel and efficient strategy for the synthesis of various carbamates using carbamoyl chlorides under solvent-free and grinding conditions using microwave irradiation

We present an efficient,fast and simple strategy of generating the intermediate carbamoyl chlorides from secondary amines using stoichiometric amounts of bis(trichloromethyl)carbonate(BTC) in solution and solvent-free conditions with excellent yields.The results obtained showed the yield increasing on whether a base was used.Finally,an efficient and rapid synthesis of variety carbamate derivatives was developed by the reaction with a high variety of different alcohols,phenols,diols and this intermediate at room temperature with grinding and in solvent-free conditions under microwave irradiation.The presence of various safe bases is shown to be effective in reducing the reaction times,increasing the yields and easing purification.The present method does not involve any hazardous phosgene.     

Plasma etching of III–V semiconductors in BCl3 chemistries: Part II: InP and related compounds

BCl₃/Ar and BCl₃/N₂ plasma chemistries were compared for patterning of InP, InAs, InSb, InGaAs, InGaAsP, and AlInAs. Under electron cyclotron resonance conditions etch rates in excess of 1 μm/min can be achieved at room temperature with low additional rf chuck power (150 W). The etch rates are similar for both chemistries, with smoother surface morphologies for BCl₃/Ar. However, the surfaces are still approximately an order of magnitude rougher (as quantified by atomic force microscopy) than those obtained under the same conditions with Cl₂/Ar. InP surfaces etched at high BCl₃-to-Ar ratios have measurable concentrations of boron-and chlorine-containing residues.     

Iodine catalyzed efficient synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride under solvent-free conditions

Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described.Mild reaction conditions,easy workup,high yield,and easily available catalyst are important features of this method.     

PEG-SO3H as an efficient and reusable catalyst for chemoselective synthesis of 1,1-diacetates

An efficient and convenient procedure of the synthesis of 1,1-diacetates from aromatic aldehydes and acetic anhydride under mild and solvent-free conditions at room temperature,in the presence of PEG-SO₃H is reported.PEG-SO₃H acts as a catalyst and can be recovered and reused eight times without apparent loss of its catalytic activity.     

A convenient synthesis of pyrroles catalyzed by acidic resin under solvent-free condition

<正>A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition.Macroporous strongly acidic styrol resin(D001) as a novel,efficient,cost-effective,and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions.The pyrroles were obtained in high yields in short reaction times.     

Selective monotetrahydropyranylation of symmetrical diols using P2O5/SiO2 under solvent-free conditions and their depyranylation

Selective protection of one of the hydroxyl group in 1, n-symmetrical diols is achieved by P2O5/SiO2-catalyzed reaction of the diol with dihydropyran under solvent-free conditions at room temperature. This selective protection is simple and it occurred under economically cheap conditions in high yield. The deprotected diol is simply obtained by refluxing of this compound in methanol using the same catalyst without any byproduct formation or additional purifications.     

A simple and efficient method for solvent-free iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid by grinding method

<正>Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.     

Cobalt(Ⅱ) chloride accelerated one-pot three-component synthesis of α-aminophosphonates at room temperature

A simple,efficient,and general method has been developed for the one-pot,three-component synthesis ofα-aminophosphonates from condensation reaction of trimethyl phosphite,aryl aldehydes and aryl amines in the presence of CoCl₂-6H₂O under solvent-free conditions.Thusα-aminophosphonates were synthesized relatively quickly in good yields at room temperature.     

室温快速合成SnSe纳米棒

The synthesis of crystalline SnSe nanorods was successfully achieved via a chemical reaction between sodium selenosulfate (Na₂SeSO₃) and SnCl₂·2H₂O in alkaline aqueous solution in the presence of the complexing agent (trisodium citrate) at room temperature under ambient air. The product was characterized by X-ray diffraction (XRD), transmission electron microscopoy (TEM) and X-ray photoelectron spectroscopy (XPS). The results reveal that the SnSe nanorods are well crystalline with an average diameter of 85 nm and the lengths up to 10 μm. The possible mechanism for the formation of SnSe is also discussed.     

Chemoselective and Catalytic Trimethylsilylation of Alcohols and Phenols by 1,1,1,3,3,3-Hexamethyldisilazane and Catalytic Amounts of PhMe3N+Br3–

 An efficient procedure for the trimethylsilylation of alcohols and phenols is presented. The combination of 1,1,1,3,3,3-hexamethyldisilazane and a catalytic amount of phenyltrimethylammonium tribromide (PhMe3N+Br3?) was found to be effective for the trimethylsilylation of alcohols and phenols. The protection reaction is very simple and homogenously performed in dichloromethane at room temperature and mild conditions.     

Iodine-catalyzed Efficient Synthesis of β-Keto Esters from Aldehydes and Ethyl Diazoacetate Under Solvent-free Conditions

An efficient procedure for the synthesis of β-keto esters from the reaction of aldehydes and ethyl diazoa-cetate catalyzed by iodine at room temperature under solvent-free conditions has been described. The catalytic procedure has the advantages of easily available catalyst,mild reaction conditions,high yields,and easy work-up.     

Reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride under solvent free conditions

<正>A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH_4/silica chloride at room temperature,afforded excellent yield of the corresponding amines.     

天门冬氨酸催化1,1,1,3,3,3-六甲基二硅氮烷硅烷化羟基为三甲基硅醚(英文)

A wide variety of alcohols and phenols were protected as trimethylsilyl ethers using 1,1,1,3,3,3-hexamethyl disilazane catalyzed by aspartic acid as a non-toxic,metal-free,and green organocatalyst at room temperature in acetonitrile under mild and heterogeneous conditions.The procedure is operationally simple and the silylated product was obtained in high yield and purity.