非烯胺途径有机催化醛醇缩合反应立体选择性合成邻卤代醇和Knoevenagel产物（英文）

Stereoselective synthesis by an aldol reaction between chloroacetone and aldehyde was studied using a synthesized chiral organocatalyst and triethylamine. The reaction gave α-chloro-β-hydroxy ketones in excellent yield with high anti selectivity and enantioselectivity. The chiral organocatalyst was also used in the Knoevenagel reaction, which gave α-cyano-β-hydroxy ketones at a low temperature and the usual Knoevenagel product at a high temperature. Both products were obtained in good to moderate yield with good anti selectivity in the case of α-cyano-β-hydroxy ketone derivatives.     

Stereoselective synthesis ofvic-halohydrins and an unusual Knoevenagel product from an organocatalyzed aldol reaction：A non-enamine mode

Stereoselective synthesis by an aldol reaction between chloroacetone and aldehyde was studied using a synthesized chiral organocatalyst and triethylamine. The reaction gave α-chloro-β-hydroxy ketones in excellent yield with highantiselectivity and enantioselectivity. The chiral organocatalyst was also used in the Knoevenagel reaction, which gave α-cyano-β-hydroxy ketones at a low tem-perature and the usual Knoevenagel product at a high temperature. Both products were obtained in good to moderate yield with goodanti selectivity in the case of α-cyano-β-hydroxy ketone deriva-tives.     

Solid state reactions of nitrogenous heterocyclic compounds (Ⅱ)——Solid state reactions of indole with carbonyl compounds

Solid state Michael addition reaction of indole with α,β-unsaturaled carbonyl compounds was carried out,by which a series of compounds containing three different heterocyclic groups binding to one carbon atom were obtained.In the presence of Lewis acid,indole could undergo the solid state condensation reaction with aromatic ketones and aldehydes or quinones.The solid state reaction showed higher selectivity and yield than solution reaction The structures of products were identified by IR,1H NMR,MS,elemental analysis and X-ray crystal analysis.The reaction mechanism was also proposed.     

A Convenient Synthesis of Conjugated Acetylenic Ketones by Copper(l)-Catalyzed under Microwave Irradiation

Alkynyl ketones are useful precursors and intermediates in synthetic organic chemistry1 and has evoked considerable interest. A number of methods for the synthesis of conjugated acetylenic ketones involve the reaction a metal acetylide with an acyl chlorides or another carboxylic acid derivative have been developed 2. Recently, the synthesis of α, β-conjugated acetylenic ketones catalyzed by Pd(Ⅱ) or by copper(Ⅰ)pd(Ⅱ) reaction of 1-alkynes and acyl chlorides have been described. The acylation of terminal alkynes by acyl chlorides in the presence of catalytic amounts copper(Ⅰ) salts leading to α, β-conjugated acetylenic ketones has also been reported. However, many of these reactions suffer from lack of high pressure (17 atm), long reaction time (30 h)and require low temperatures (-78℃). Our work involves the synthesis of conjugated acetylenic ketones via the reaction of terminal alkynes with aroyl chlorides in the presence of cuprous iodide under microwave irradiation conditions.     

Stereoselective Synthesis of Sulfonyl-substituted trans-2,3-Dihydrofuran Derivatives via Reaction of Arsonium Ylides with α,β-Unsaturated Ketones

Trans-2,3-dihydrofuran derivatives 3 or 4 substituted with a sulfonyl group were prepared with high chemoselectivity and good yields by [1＋4]-addition reaction of α,β-unsaturated ketones 1 with arsonium bromide 2 in CH2Cl2 in the presence of potassium carbonate at room temperature.The structures of the products were characterized by IR,MS,^1H NMR,elemental analysis and single crystal X-ray diffraction analysis.A mechanism for the formation of products was also proposed.     

Novel Phenomenon of Oxygen-to-oxygen Silyl Migration in Directed Aldol Reaction

The phenomenon of migration of the silyl groups from α-oxygen to β-oxygen in sodium aldol reaction was observed for the first time in this paper.     

A theoretical study on the water-mediated asynchronous addition between urea and formaldehyde

The reaction between urea and formaldehyde in water solution was theoretically investigated by using B3LYP and MP2 methods.It was found that the addition of the nitrogen atom in urea to the carbonyl group in formaldehyde precedes the proton transfer and the proton migration from water to the carbonyl group occurs before the proton abstraction from the nitrogen.With one or two water molecules involved in the TS.the activation energy barrier is lowered compared to the TS of the mechanism with no water participation.The energy change along the reaction coordinate clearly shows that a zwitterionic-like intermediate does not exist on the PES.The reaction between urea and formaldehyde occurs in a concerted mechanism but with asynchronous characters.This is different from the stepwise mechanism recently found for the amination reactions of formaldehyde.     

Reductive Deoxygenation of Carbonyl to Methylene

The reductive deoxygenation of aldehydes and ketones into the corresponding alkanes is accomplished by LiAlH4, in the presence of Lewis acid InBr3. It provides a convenient method to complete the transformation from carbonyl compounds to alkanes.     

Reductive Deoxygenation of Carbonyl to Methylene by LiAlH4／InBr3

The reductive deoxygenation of aldehydes and ketones into the corresponding alkanes is accomplished by LiAlH4 in the presence of Lewis acid InBr3. It provides a convenient method to complete the transformation from carbonyl compounds to alkanes.     

PhI(OAc)_2-promoted umpolung acetoxylation of enamides for the synthesis of α-acetoxy ketones

Umpolung is a fundamental concept in organic chemistry, which provides an alternative strategy for the synthesis of target compounds which were not easily accessible by conventional methods. Herein, a mild and efficient PhI(OAc)_2-promoted umpolung acetoxylation reactions of enamides was developed for the synthesis of α-acetoxy ketones. The reaction tolerates a wide range of functional groups and affords α-acetoxy ketones in good to excellent yields. PhI(OAc)_2 serves as a source of acetoxy in the reaction.     

SYNTHESIS AND FREE RADICAL POLYMERIZATION OF 2-OXO-3-METHYLEN E-5-PHENYL-1,4-DIOXAN

The novel cyclic monomer, 2-oxo-3-methylene-5-phenyl-1,4-dioxan, was synthesized by a set of reactions. Several intermediates were prepared and characterized in order to determine the monomer structure. The presence of chiral centers in the intermediates and resulting monomer makes it complicated to separate , purify and characterize them. It is a very reactive monomer which will polymerize even at room temperature if expose to moisture and air. This monomer can undergo essentially quantitative flee radical ring opening polymerization. The driving force for ring opening is the formation of new carbonyl group and benzylic radical. The monomer and polymer structure were established by IR, ~1H NMR, ~(13)C NMR and elemental analysis or high resolution mass spectrum. The molecular weight of the resulting polymer was estimated by viscosity determination.     

Regioselective 1,2-Addition of Ti(IV)-enolate to α, β–Unsaturated Compounds

The nucleophilic addition to α, β-unsaturated carbonyl compounds is a fundamental C-C bond forming reaction in organic chemistry1. Since there are two reaction sites in the α, β–unsaturated carbonyl group, the regioselectivity of the nucleophilic addition (1, 2 vs. 1, 4 addition) is of primary importance when applying this type of reaction in organic synthesis. Factors that control the regioselectivity include the softness and hardness of the attacking nucleophiles2, solvent and temperatu…     

Asymmetric annulations based on cycloisomerization of cyclopropyl tethered allenyl ketones by bimetallic relay catalysis

The diastereo-and enantioselective tandem cycloisomerization/[4 + 2]-cycloaddition reaction of cyclopropyl tethered allenyl ketones with α,β-unsaturated carbonyl compounds was realized firstly under mild reaction conditions by using bimetallic silver(I)/chiral metal-N,N′-dioxide catalysts, providing a facile and atom-economic route to enantioenriched polysubstituted furopyran derivatives with good results. Possible transition state models were proposed to explain the stereoinduction.     

Unusual Reaction of β-Hydroxy α-Diazo Carbonyl Compounds with Trichloroacetonitrile (CI3CCN) and Sodium Hydride

In the process of preparing α-diazo carbonyl compound 2 by imidation of 1, we unexpectedly observed a direct conversion of the hydroxyl group into trichloroacetylamino group. In this presentation, we report this unprecedented reaction, as well as the Rh2(OAc)4-catalyzed reaction of the resulting β-(trichloroacetyl)amino β-diazo carbonylcompounds 3. [ 1]     

A Facile and Efficient Oxidation of α,β-Unsaturated Alcohols with Manganese Dioxide in Ionic Liquids under Mild Conditions

The oxidation of α,β-unsaturated primary and secondary alcohols to corresponding aldehydes and ketones by manganese dioxide in ionic liquids as a safe recyclable and accelerative reaction medium under mild conditions are described. The rate of the oxidation reaction is faster and the yield is higher than that with conventional procedures.     

An Efficient One-pot Synthesis of β-Amino/β-Acetamido Carbonyl Compounds via ZrCl4-catalyzed Mannich-type Reaction

Zirconium(IV) chloride catalyzed efficient one-pot synthesis of β-amino/β-acetamido carbonyl compounds at room temperature is described. In the presence of ZrCl4, the three-component Mannich-type reaction via a variety of in situ generated aldimines, with various ketones, aromatic aldehydes and aromatic amines in ethanol, led to the formation of β-amino carbonyl compounds and the four-component Mannich-type reaction of aromatic aldehydes with various ketones, acetonitrile and acetyl chloride resulted in the corresponding β-acetamido carbonyl compounds in high to excellent yields. This methodology has also been applied towards the synthesis of dimeric β-amino/β-acetamido carbonyl compounds.     

Catalyst-free,radical-mediated intermolecular 1,2-arylheteroarylation of alkenes by cleaving inert C–C bond

A novel photoinduced intermolecular 1,2-arylheteroarylation of alkenes and the efficient synthesis of valuable polyarylalkanes are reported. The reaction is operationally simple, proceeds under mild conditions and with no additional catalyst and reagents.The strategically designed radical cascade reaction is enabled by electron transfer, and involves cleavage of an inert C–C bond.The process features broad functional group compatibility as well as high product transformability.     

Electrochemical Studies of 1,4-Bis[2-(2-pyridyl)-vinyl] Benzene and 1,4-Bis[2-(4-pyridyl) vinyl] Benzene Laser Dyes via Cyclic Voltammetry, Convolutive Voltammetry and Digital Simulation Methods

Electrochemical properties of two diolefinic laser dyes namely 1,4-bis[2-(2-pyridyl)-vinyl] benzene (2PVB) and 1,4-bis[2-(4-pyridyl) vinyl] benzene (4PVB) have been investigated using cyclic voltammetry and convolutive voltammetry combined with digital simulation at a platinum electrode in 0.1 mol/L tetrabutyl ammonium perchlorate (TBAP) in the two different solvents acetonitrile (CH3CN) and dimethylformamide (DMF). The species were reduced via consumption of two sequential electrons to form radical anion and dianion. In switching the potential to positive direction, the two compounds were oxidized by loss of one electron, which was followed by a fast isomerisation process. The electrode reaction pathway and the electrochemical parameters of the investigated compounds were determined using cyclic voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation and convolutive voltammetry methods.     

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.     

Regioselective 2-alkylation of indoles with α-bromo esters catalyzed by Pd/P,P=O system

A palladium-catalyzed 2-alkylation of indoles with α-bromo esters is developed by employing a P,P=O ligand. The method features excellent regioselectivities, mild reaction conditions, and good functional group compatibility. The employment of the P,P=O ligand as well as 4 A molecular sieves were crucial for the success of the transformation. Mechanistic studies indicate the reaction proceed through a radical pathway.