Photochemically Catalyzed Diels-Alder Reaction of Azadienes with 2,3-Dihydrofuran by 2, 4, 6-Triphenylpyrylium Salt： Synthesis of Styrylfuroquinoline Derivatives

Photochemically promoted Diels-Alder reactions of 1, 4-diaryl-1-azabutadienes with 2,3-dihydrofuran were achieved by using 2, 4, 6-triphenylpyrylium tetrafluoroborate as catalyst to produce corresponding styrylfuroquinolines in high yield.     

Synthesis of 1, 4-Bis[3-N-propionyl-2-aryl-1, 3, 4- oxadiazoline-5-yl]phenylenes

1, 3, 4-Oxadiazoline derivatives are found to possess significant biological activities such as antifungal1, insecticidal2, CNS depressant3-5, anticonvulsant effects and plant growth accelerator. They are highly important heterocycles, and have been used …     

Design and Synthesis of 3, 4-Dihydropyrrolo[2, 1-c][1, 4]oxazin-l-one and its 7-Acyl Derivatives

Starting from 1H-pyrrole, unreported 3, 4-dihydropyrrolo[2, 1-c][1, 4]oxazin-1-one 4, 7-(4-chlorobenzoyl)-3, 4-dihydropyrrolo[2, 1-c][1, 4]oxazin-1-one 5 and 7-benzoyl-3, 4-dihydro-pyrrolo [2, 1-c][1, 4]oxazin-1-one 9 were designed and synthesized. They may have antipyretic and analgesic activities.     

Multicomponent Reaction in Ionic Liquid： A Novel and Green Synthesis of 1, 4-Dihydropyridine Derivatives

1, 4-Dihydropyridine (DHP) heterocyclic ring is a common feature of various bioactivecompounds such as vasodilator, bronchodilator and antiatherosclerotic, antitumor, andantidiabetic agents1. Due to their important pharmacological activities, many methods…     

Synthesis of Some Potential Antiangiogenic 1,3-Dihydro-l,3-dioxo-2H-isoindole Derivatives

Based on the structure-activity relationships of RGD-containing peptides, a series of 1,3-dihydro-l,3-dioxo-2H-isoindole derivatives were synthesized. All of them were first reported.Their structures were confirmed by spectral data and elemental analysis. Their ability to inhibit angiogenesis were evaluated in the chick embryo chorioallantoic membrane assay at -10^-5 mol/L.Compounds 5b and 5e displayed obviously antiangiogenic activity.     

Synthesis of 1-Benzoyl-3-aryl-4-hydroxy-4-phenylimidazolidin-2-thiones

l-Benzoyl-3-aryl-4-hydroxy-4-phenylimidazolidin-2-thiones can be synthesized readily from the cyclization of 1-benzoyl-3-arylthioureas with bromine-acetophenone in the presence of excess triethylamiqe.     

Synthesis and Bioactivity of Novel Aminomethyl-2-（1, 2,4-triazol）-4, 4-dimethyl-3-pentanone （ol）

3, 3-Dimethyl-1-(1,2,4-triazol)-2-butanone was treated with aqueous formaldehyde to give an additional product, and subsequent elimination by acetic anhydride yielded 4,4-dimethyl-2-(1,2,4-triazol)-1-penten-3-one. Further addition with substituted amines provideda series of (1,2,4-triazol)-4,4-dimethyl-3-pentanone, which were then reduced by KBH4 to obtaina series of (1,2,4-triazol)-4,4-dimethyl-3-pentanol. Their structures were confirmed by ^1HNMR and elemental analysis. The results of bioassay showed that the title products possess good fungicidal activities.     

Design and Synthesis of p/m-[p-（un）Substituted Phenylsulfonamido]phenyl β-Diketo Acids and Quinoxalone Derivatives

Diketo acid derivatives are potent and selective HIV-1 integrase inhibitors. To investigate the detailed synthesis of those derivatives, a series of p/m-[p-（un）substituted phenylsulfonamido]phenyl β-diketo acid derivatives have been designed and synthesized. The quinoxalone derivatives as the potential bioisosteres of the biologically labile β-diketoacid pharmacophores have also been synthesized from reactions of the corresponding diketo acids with o-phenylenediamine. The structures of all diketo acid （ester） and quinoxalone derivatives were confirmed by 1^H NMR, 13^C NMR, IR, HRMS and/or MS （ESI）. X-ray crystallographic analysis of 11b demonstrates a similar arrangement of the side chain of quinoxalone derivatives with the parent diketoacids due to the intramolecular hydrogen bond （O…H-N） and the sp^2 hybridization configuration of the two nitrogen atoms of the quinoxalone ring.     

Asymmetric Pictet-Spengler Reactions：Synthesis of Tetrahydroisoquinoline Derivatives from L-DOPA

The cis-l-substituted-6,7-dihydroxy-l,2,3,4-tetrahydroisoquinoline-3-carboxylic acid esters 3 can be obtained in a highly diastereoselective fashion through 1,3-induction Pictet- Spengler(P-S) cyclization of the L-DOPA (3,4-dihydroxyphenylalanine) methyl ester with aromatic or aliphatic aldehydes under acidic conditions. Their epimers 4 are also obtained as minor products.     

Novel Synthesis of α‐Diketones from Bisbenzimidazolium Salt and Grignard Reagents

The reaction of bisbenzimidazolium salt with Grignard reagents and a new synthetic method of a‐diketones from bis‐benzimidazolium salt and Grignard reagents are reported. The structures of all a‐diketones are characterized by elemental analyses, infrared spectroscopy and ¹H NMR spectroscopy. The influences of the various Grignard reagents on the yield of a‐diketones and the mechanism are discussed, and a new convenient synthetic method for a‐diketones is provided.     

Studies on New Additions to 5-Methoxy-2 (5H)-Furanone: 1, 4-Addition of Grignard Reagents, and 1,3-Dipolar Cycloaddition of Silyl Nitronates

Recently, much effort has been made in the development of generally applicable organic synthesis of 5-alkyloxy-2(5H)-furanones due to their essential structure entities in the synthesis of some biologically active natural products and their application as useful intermediates in organic synthesis1. Their reactions such as Michael addition, Diels-Alder reaction and photocatalyzed conjugate addition have been studied extensively2-4.However, Michael addition reaction of Grignard reagents to 5-m…     

Addition of Organolithium and Grignard Reagents to Pyrimidine-2(1H)-thione: Easy Access to 4-Substituted 3,4-Dihydropyrimidine-2(1H)-thiones

Organolithium and Grignard reagents are added to pyrimidine-2(1H)-thione, yielding 4-substituted 3,4-dihydropyrimidine-2-(1H)-thiones. Since the synthetic procedure can be performed on a multigram scale, and since pyrimidine-2(1H)-thione as well as the majority of organometallic reagents are readily available, the process described provides an easy access and complementary to other methods to 4-substituted 3,4-dihydropyrimidine-2-(1H)-thiones.     

Copper-Catalyzed Addition of Grignard Reagents to in situ Generated Indole-Derived Vinylogous Imines

Chiral indole derivatives are ubiquitous motifs in pharmaceuticals and alkaloids. Herein, the first protocol for catalytic asymmetric conjugate addition of Grignard reagents to various sulfonyl indoles, offering a straightforward approach for the synthesis of chiral 3-sec-alkyl-substituted indoles in high yields and enantiomeric ratios is presented. This methodology makes use of a chiral catalyst based on copper phosphoramidite complexes and in situ formation of vinylogous imine intermediates.     

Conversion of 3-Carbethoxy-4-methyl Coumarin Derivatives into Several New Annelated Coumarin Derivatives

The reaction of ethyl esters of 4-methyl-2-oxo-2H-l-benzo(naphtho) pyran.3-carboxylic acids (1) with aromatic aldehy-des in the presence of piperidine yielded 4-styryl-3-carboxami-dopiperidyl connmrin derivatives 4. The reaction of hydrazlne hydrate with 1 gave acetophenone hydrozone derivatives 5 and acetophenone azine derivatives 6. The reaction of 1 with prima-ry amines afforded compomlds 7—9. And the treatment of la with Grignard reagents afforded 3-aroyl-4-methyl coumarin derivatives 10.     

Grignard试剂与α-肉桂酰基环二硫缩烯酮的区域选择性加成反 应

乙基、丙基、丁基、苯基和苄基卤化镁等Grignard试剂与具有三个亲电中心的α-肉桂酰基环二硫缩烯酮类化合物2反应,加成反应发生在2中与芳基相邻的碳原子上,生成共轭加成产物3,反应具区域选择性。     

利用Grignard试剂的甲酰化反应合成对甲氧基苯甲醚

二取代苯并咪唑盐;利用Grignard试剂的甲酰化反应合成对甲氧基苯甲醚     

Introducing Deep Eutectic Solvents to Polar Organometallic Chemistry: Chemoselective Addition of Organolithium and Grignard Reagents to Ketones in Air

Despite their enormous synthetic relevance, the use of polar organolithium and Grignard reagents is greatly limited by their requirements of low temperatures in order to control their reactivity as well as the need of dry organic solvents and inert atmosphere protocols to avoid their fast decomposition. Breaking new ground on the applications of these commodity organometallics in synthesis under more environmentally friendly conditions, this work introduces deep eutetic solvents (DESs) as a green alternative media to carry out chemoselective additions of ketones in air at room temperature. Comparing their reactivities in DES with those observed in pure water suggest that a kinetic activation of the alkylating reagents is taking place, favoring nucleophilic addition over the competitive hydrolysis, which can be rationalized through formation of halide‐rich magnesiate or lithiate species.     

新型1,2,4-三取代-1,2,3-三氮唑盐的合成

以邻溴苄醇(1)和水杨醛(2)为原料,经5步反应合成了一种分子内同时具有羟基和1,2,3-三氮唑环的新型类卡宾前体盐中间化合物(7),在三氟甲磺酸酐的催化下,分子内六元环化反应得到一种新型的1,2,4-三取代-1,2,3-三氮唑并三环体系类卡宾前体盐(8),其结构经1H NMR,13C NMR和MS(ESI)表征。     

Asymmetric Conjugate Addition of Grignard Reagents to 3‐Silyl Unsaturated Esters for the Facile Preparation of Enantioenriched β‐Silylcarbonyl Compounds and Allylic Silanes

A highly enantioselective conjugate addition of Grignard reagents to 3‐silyl unsaturated esters to deliver synthetically useful chiral β‐silylcarbonyl compounds was developed. The synthetic value of this methodology was further illustrated by the synthesis of enantioenriched β‐hydroxyl esters and the facile access granted to various α‐chiral allylic silanes. A plethora of diastereoselective transformations of β‐silylenolates were also investigated and afforded manifold organosilanes that contained contiguous stereogenic centers with excellent enantioselectivity.