Chemoselective Dithioacetalization of Carbonyl Compounds Using Magnesium Hydrogensulfate as Efficient Heterogeneous Catalyst

Carbonyl compounds have been successfully converted into their corresponding dithiolanes and dithianes derivatives with 1,2-ethanedithiol and 1,3-propanedithiol in excellent yield at room temperature and short reaction times using a catalytic amount of magnesium hydrogensulfate. The synthetic simple procedures reported in this paper constitute an exceptionally mild procedure for carbonyl protection in ambient conditions.     

An Efficient and Mild Deprotection of 1,3-Oxathiolanes to Carbonyl Compounds Using the Superoxide Ion

An efficient deprotection of 1,3-oxathiolanes to carbonyl compounds has been achieved under the mild reaction conditions of tetraethylammonium superoxide in an aprotic medium at room temperature.     

Montmorillonite KSF,a Mild and Efficient Catalyst for Benzodithiepination of Carbonyl Compounds

A mild and efficient procedure for the protection of carbonyl compounds as 1,5-dihydro-3H-2,4-benzodithiepines in high yields is described by using a readily available and inexpensive KSF clay catalyst.     

Trimethylsilyl bis(Fluorosulfonyl)imide : An Efficient Catalyst for the Addition of Trimethylsilyl Cyanide to Carbonyl Compounds

In the presence of 1 mol% of trimethylsilyl bis(fluorosulfonyl)imide, trimethylsilyl cyanide adds efficiently to carbonyl compounds. The catalyst has been found to be more active than trimethylsilyl triflate for the above reaction.     

An Efficient Stereocontrolled Synthesis of Di-and Triunsaturated Carbonyl Compounds

ω-chlorodienals, ω-chlorodienones and 1,6-diacyl-1,3,5-hexatrienes were easily obtained from (E)-and (Z)-dichloroethylenes.     

An Efficient and Mild Preparation of Vinyl Diazo Carbonyl Compounds

The combination of (CF3CO)2O/Et3N is found to be a mild and efficient dehydration condition for β-hydroxy-α-diazo compounds.     

Synthesis of a Novel Carbon Based Acid Catalyst and Its Catalytic Activity for the Acetalization and Ketalization

A novel carbon based strong solid acid catalyst has been synthesized successfully. The catalytic activity for acetalization and ketalization was investigated. The results showed that the novel catalyst was very efficient with the average yield over 92%. The novel heterogeneous catalyst also has the advantages of high activity, wide applicability even to the preparation of 7 membered ring acetals and ketals, strikingly simple workup procedure, non-pollution and reusability, which will contribute to the green process greatly.     

Chemoselective Dithioacetalization and Oxathioacetalization of Carbonyl Compounds Using Alumina Sulfuric Acid as Catalyst

Carbonyl compounds have been successfully converted into their corresponding dithiolane, dithiane, and oxathiolane derivatives using a catalytic amount of alumina sulfuric acid (Al₂O₃–SO₃H) with excellent yields at room temperature in short reaction times under mild conditions. This simple method is a highly chemoselective procedure for protection of aldehydes in the presence of ketones, and the heterogeneous catalyst can be recovered and reused several times without any loss of its activity.     

Mild and Efficient Method for Oxathioacetalization of Carbonyl Compounds

An efficient procedure for the protection of carbonyl compounds into the corresponding 1,3‐oxathioacetal has been achieved using PAS as catalyst.     

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.     

一种高效可循环的有机介孔树脂负载的N-杂卡宾络合钯催化剂催化的Sonogashira反应

新型有机介孔材料FDU-15负载卡宾配体络合醋酸钯催化剂FDU-NHC/Pd(Ⅱ)的制备方法简单,通过三步反应即可制得,采用X射线衍射、N2吸附-脱附和透射电镜等手段对催化剂进行了表征,并考察了它在Sonogashira偶联反应中的催化性能.结果表明,功能化不影响FDU-15的有序介孔结构,仅其孔径、孔体积和BET比表...     

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…     

Ozone Oxidation of Oximes to Carbonyl Compounds

An efficient and convenient conversion of oximes to corresponding carbonyl compounds with ozone is reported.     

简单芳香族醛、酮化合物相转移催化Kishner-Wolff反应

Kishner-wolff反应(简称K-W反应)是1911-1912年发现的,它是还原醛和酮的腙或缩氨脲为烃的著名方法。黄鸣龙、Cram、Grundon等人曾研究过此反应。1979年,我们用冠醚作相转移催化剂实现了相转移催化K-W反应。本文探讨了相转移催化K-W反应的适用范围。研究了八个芳香族醛、酮化合物的还原,其结果列于表1。     

Silver‐Catalyzed Oxidative Coupling of Aniline and Ene Carbonyl/Acetylenic Carbonyl Compounds: An Efficient Route for the Synthesis of Quinolines

An efficient silver‐mediated coupling of aniline with ene carbonyl/acetylenic carbonyl compounds for the synthesis of quinolines is reported. The transformation is effective for a broad range of substrates, thus enabling the expansion of substituent architectures on the heterocyclic framework. The electronic properties of the substituents on the amine have been investigated. It was found that molecules with both electron‐donating and electron‐withdrawing substituents were suitable substrates for this transformation, and the expected products were obtained in moderate to excellent yields. The use of a single catalytic system to mediate chemical transformations in a synthetic operation is important for the development of new atom‐economic strategies and this strategy is efficient in building complex structures from simple starting materials in an environmentally benign fashion.     

N-Methyl Morpholine Chlorochromate: An Efficient Reagent for Oxidation of Primary and Secondary Alcohols to Carbonyl Compounds

Instantaneous generation of N-methyl morpholine chlorochromate (NMMCC) is an efficient reagent for oxidation of primary and secondary alcohols to the corresponding carbonyl compounds. The comparison of reaction time and product yield was studied with novel NMMCC and other chlorochromate reagents and shows that the presented method requires less reaction time with good yield at laboratory temperature. The synthesis of reagent, formation of toxic and hazardous chromylchloride have been avoided, and also use of NMMCC under microwave irradiation for oxidation leads to fast reaction time and success of the strategy.     

A Highly Efficient Bismuth Nitrate/Keto-ABNO Catalyst System for Aerobic Oxidation of Alcohols to Carbonyl Compounds under Mild Conditions

An efficient and practical catalytic system for the oxidation of alcohols to aldehydes/ketones using catalytic amounts of Bi(NO₃)₃ and Keto-ABNO (9-azabicyclo [3.3.1]nonan-3-one N-oxyl) with air as the environmentally benign oxidant was developed. Various primary and secondary alcohols were smoothly oxidized to the corresponding products under mild conditions, and satisfactory yields were achieved. Moreover, this methodology avoids the use of a ligand and base. The gram-scale reaction was demonstrated for the oxidation of 1-phenyl ethanol, and the product of acetophenone was obtained at an isolated yield of about 94%.     

Quinolinium Fluorochromate: An Efficient and Convenient Reagent for Oxidative Cleavage of Thioacetals to Their Parent Carbonyl Compounds

Deprotection of thioacetals to their parent carbonyl compounds in high yields has been carried out using quinolinium fluorochromate under mild conditions.     

Terpyridine Diphosphine Ruthenium Complexes as Efficient Photocatalysts for the Transfer Hydrogenation of Carbonyl Compounds

The cationic achiral and chiral terpyridine diphosphine ruthenium complexes [RuCl(PP)(tpy)]Cl (PP=dppp ( 1 ), (R,R)-Skewphos ( 2 ) and (S,S)-Skewphos ( 3 )) are easily obtained in 85–88 % yield through a one-pot synthesis from [RuCl₂(PPh₃)₃], the diphosphine and 2,2′:6′,2′′-terpyridine (tpy) in 1-butanol. Treatment of 1 – 3 with NaPF₆ in methanol at RT affords quantitatively the corresponding derivatives [RuCl(PP)(tpy)]PF₆ (PP=dppp ( 1 a ), (R,R)-Skewphos ( 2 a ) and (S,S)-Skewphos ( 3 a )). Reaction of [RuCl₂(PPh₃)₃] with (S,R)-Josiphos or (R)-BINAP in toluene, followed by treatment with tpy in 1-butanol and finally with NaPF₆ in MeOH gives [RuCl(PP)(tpy)]PF₆ (PP=(S,R)-Josiphos ( 4 a ), (R)-BINAP ( 5 a )) isolated in 78 % and 86 % yield, respectively. The chiral derivatives have been isolated as single stereoisomers and 3 a , 4 a have been characterized by single crystal X-ray diffraction studies. The tpy complexes with NaOiPr display high photocatalytic activity in the transfer hydrogenation (TH) of carbonyl compounds using 2-propanol as the only hydrogen donor and visible light at 30 °C, at remarkably high S/C (up to 5000) and TOF values up to 264 h⁻¹. The chiral enantiomers 2 , 2 a and 3 , 3 a induce the asymmetric photocatalytic TH of acetophenone, affording (S)- and (R)-1-phenylethanol with 51 and 52 % ee, respectively, in a MeOH/2-propanol mixture.