Convenient one-pot formation of highly functionalized 5-bromo-2-aminothiazoles,potential endocannabinoid hydrolase MAGL inhibitors

Highly functionalized 5-bromo-2-amino-1,3-thiazoles bearing various substituents could be easily prepared by a rapid and efficient one-pot method, using simple starting materials and mild conditions while avoiding the use of metal catalysts or inconvenient reagents such as elemental halogens. These useful products can serve as starting materials for other reactions or as pharmacologically interesting compounds. In our work we have shown that the resulting 5-bromothiazole compounds could lead to monoacylglycerol lipase (MAGL) inhibition in the μM range.     

Oxidative ring opening of furan derivatives to α,β-unsaturated γ-dicarbonyl compounds,useful intermediates for 3-oxocyclopentenes synthesis

α,β-unsaturated γ-dicarbonyl compounds, easily obtained by reaction of pyridinium chlorochromate with alkylfurans, are interesting starting materials for the rapid synthesis of 3-oxo-cyclopentenes.     

Synthesis of (E)-alpha,beta-unsaturated amides with high selectivity by using samarium diiodide

Stereoselective beta-elimination of 2-chloro-3-hydroxyamides 1 is achieved by using samarium diiodide to yield alpha,beta-unsaturated amides 2, in which the C=C bond is di- tri-, or tetrasubstituted. The starting compounds 1 are easily prepared by reaction of the corresponding lithium enolates of alpha-chloroamides with aldehydes or ketones at - 78 degrees C. The influence of the reaction conditions and the structure of the starting compounds on the stereoselectivity of the beta-elimination reaction is also discussed.     

新农药研究（Ⅲ）：咪唑啉酮类化合物的合成

Rovral[3-(3,5-二氯苯基)-1-异丙氨基甲酰乙内酰脲]是一种优良的广谱杀菌剂和种子处理剂,由于3,5-二氯苯胺不易制备,本文采用其它取代苯胺作为起始原料,采用固态光气制备异氰酸酯,中间体未经分离,经缩合、关环“一锅法”反应,得到化合物Ⅰ,进一步反应得到Ⅱ、Ⅲ系列新化合物。     

Michael Addition of Activated Nitriles to 4[(+)-Camphor-10′-Sulfonylamino]acetophenone and Some of its Chalcones

4-[(+)-Camphor-10'-sulfonylamino]acetophenone ( 2 ) and some of its chalcones 3 were easily prepared in quantitative yields starting from (+)-camphor-10-sulfonyl chloride. Several new 2-oxo-, 2-thio-, as well as 2-amino-pyridines carrying the camphor sulfonylamino group as a substituent were synthesized easily in one step by Michael addition of several activated nitriles to compounds 2 and 3 . The synthesis of some fused pyridines also was investigated.     

Synthesis of (Z)-vinylsilanes with high diastereoselectivity by using samarium diiodide

beta-Elimination of O-acetyl 1-chloro-1-trimethylsilylalkan-2-ols 1 was achieved by using samarium diiodide as a metaling reagent and afforded the corresponding (Z)-vinylsilanes with high stereoselectivity. The starting compounds 1 were easily prepared by treatment of different aldehydes with (chlorolithiomethyl)trimethylsilane and further acetylation.     

Synthesis and characterization of nitro-p-xylenes

In this paper we elected to nitrate p-xylene because this compound has only one mononitro- and trinitro- isomer. Trinitro-p-xylene was used as a starting material for the synthesis of other compounds in subsequent work. The mononitration of p-xylene can be easily carried out at 30 degrees C. Nitro-p-xylene is easily nitrated to dinitro-p-xylene at a temperature of 80 degrees C. The trinitro-p-xylene can be obtained at 120 degrees C. Single crystals of 2,3-dinitro-p-xylene and 2,3,5-trinitro-p-xylene were grown using the slow cooling method and we report the X-ray structure of the former. The thermal decomposition of the compounds was studied using differential scanning calorimetry (DSC) and thermogravimetry-derivative thermogravimetry (TG-DTG) techniques and FT-IR. The target compounds were also characterized by (1)H-NMR, (13)C-NMR and MS.     

Synthesis of aromatic (E)- or (Z)-alpha,beta-unsaturated amides with total or very high selectivity from alpha,beta-epoxyamides and samarium diiodide

Highly stereoselective synthesis of aromatic alpha,beta-unsaturated amides was achieved by treatment of aromatic alpha,beta-epoxyamides with samarium diiodide. The starting compounds 1 and 3 are easily prepared by the reaction of enolates derived from alpha-chloroamides with carbonyl compounds at -78 degrees C. A mechanism to explain this transformation is proposed.     

Formation of 1,3-oxathioles and 1,3-oxaselencles by reactions of carbonyl-stabilized sulfonium ylides with elemental sulfur and selenium

Carbonyl-stabilized sulfonium ylides readily react with elemental sulfur and selenium to afford 1,3-oxathiole and 1,3-oxaselenole derivatives, respectively, in good yields, thus providing a simple method for constructing these ring systems which uses easily accessible compounds as starting materials.     

Geotrichum candidum Assisted Synthesis of Sitophilate,Male Aggregation Pheromone of Granary Weevil

The syntheses of optically inactive Sitophilate and the optically active isomers (2S, 3S) and (2S, 3R) were completed by a simple route using easily avilable starting compounds.     

Synthesis of imidazo[4,5-b]quinoxaline 3-oxides from reactions of furazano[3,4-b]quinoxaline 1-oxides with nitrones and diazo compounds

The title compounds are prepared in good yields by simple procedures from readily available starting materials. They can be easily O-methylated by methyl iodide or deoxygenated by triphenylphosphine.     

A Stereoselective Approach to S-Vinyl Thioesters from Alkynes,Elemental Sulfur and Acyl Chlorides

Thioesters are activated derivatives of carboxylic acids and exhibit acylating propertiessimilar to carboxylic acid anhydrides'. S-vinyl thioesters are useful precursor for varioussulfur-containing compounds', however, their synthetic methods are limited and most ofthe methods need somewhat tedious procedures. Reactions of a-carbanions ofethanethioate with carbonyl compounds such as Wittig reaction, Wittig-Horner reactionand Peterson reaction give S-vinyl thioesters 3. Cu (I) --promoted coup…     

2-二氟甲氧(硫)基吡啶-5-硼酸频哪醇酯类化合物的合成

以吡啶类化合物作为起始原料,先经二氟甲基化反应在羟基或巯基上引入二氟甲基基团,再用铱催化剂活化吡啶环的C-H并直接引入硼酸频哪醇酯基团,得到目标化合物,其产物结构经¹H NMR、¹³C NMR、MS和元素分析确证。该方法具有合成路线较短、反应条件温和、原料廉价易得以及产率较高等优点。     

Novel synthesis of isoxazolo[5,4-b]quinolines

Isoxazolo[5,4-b]quinolines have been prepared by reacting 3-acyl or aroyl-2-chloro-6-alkoxy or 6,7-dialkoxyquinolines with hydroxylamine. The method is of general applicability for obtaining this class of compounds and involves the use of easily available starting materials.     

Synthesis of pyrido[1,2-a]indole malonates and amines through aryne annulation

Pyrido[1,2-a]indoles are known as medicinally and pharmaceutically important compounds, but there is a lack of efficient methods for their synthesis. We report a convenient and efficient route to these privileged structures starting from easily accessible 2-substituted pyridines and aryne precursors. A small library of compounds has been synthesized utilizing the developed method, affording variously substituted pyrido[1,2-a]indoles in moderate to good yields.     

Heterocyclic silyl enol ether chemistry: Synthesis and reactivity of 3-trimethylsiloxyfuran and 3-trimethylsiloxythiophene

The preparation of the titte compounds is reported starting from the corresponding bromo derivatives.3-Trimethylsiloxyfuran gives rise easily to cycloadditions affording bicyclic tetrahydrofuranonic systems.     

An efficient route to all stereoisomeric enantiopure 6-amino-3-alkyl-3- azabicyclo[3.2.1]octane-6-carboxylic acids

A single-step synthesis on a gram scale of four pure stereoisomers of the 6-amino-3-azabicyclo[3.2.1]octane-6-carboxylic acid was carried out using (R)-1-phenylethylamine to confer chirality. The phenylethyl group, and the p-methoxy group linked to the N-atom, are easily removed by hydrogenolysis to afford the corresponding NH-3 derivatives. A series of N-3-alkyl compounds were prepared by way of a "one-pot" deprotection-alkylation procedure starting from the above key compounds. Their biological activity has been evaluated on the GABA receptor.     

Aromatic annulation on the p-menthane monoterpenes: enantiospecific synthesis of the trans and cis isomers of calamenene and 8-hydroxycalamenene

A new enantiospecific route to sesquiterpenes of the calamenene family is described. The synthetic pathway starts from easily available 3-oxygenated-p-menthane monoterpenes and affords the title compounds by a homologation-benzannulation sequence. The trans and cis isomers of the natural compounds calamenene and 8-hydroxycalamenene were obtained in enantiopure form starting from (−)-menthone and (+)-isomenthone, respectively.     

A highly efficient method for the α,β-dehydrogenation of α-amino esters and α-amino-β-diesters

N-monochlorination of N-unprotected α-amino esters and α-amino-β-diesters was efficiently and very simply effected by using inexpensive effervescent sodium dichloroisocyanurate tablets for water disinfection in a biphasic organic solvent-water system. Subsequent dehydrochlorination provided α,β-didehydroaminoacid esters, whose hydrogenation would allow the starting compounds to be easily racemized.     

New chiral hypervalent iodine(V) compounds as stoichiometric oxidants

The synthesis and application of some new hypervalent iodine compounds bearing chiral and achiral ester motives derived from easily accessible starting materials is presented. The oxidation is carried out using dimethyldioxirane as an oxidant providing the desired compounds in moderate to high yields. A crystal structure analysis for one iodine(V) derivative is investigated. The λ⁵-iodanes are applied as stoichiometric reagents in the oxidation of thioanisole to phenylmethyl sulfoxide, benzyl alcohol to benzaldehyde, and meso-hydrobenzoine to benzaldehyde, benzyl, and benzoin.