Reaction of Trialkylphosphine Carbon Disulfide Adducts with Cyclopentadienones

Abstract

It has been known more than for 100 year that triethylphosphine forms the 1:1 adducts with carbon disulfide and isothiocyanates. However, little is know on the reaction of the adducts and the formation of reactive alkylidenephosphoranes was recently reported by the reaction of adducts with electron-poor double bonds.     

First Examples of Povarov Reaction of Cyclopentadienones

We describe herein the first examples of Povarov reaction of tetrasubstituted cyclopentadienones in the preparation of quinoline compounds. Polycyclic compounds bearing tetrahydro‐3H‐cyclopenta[c]quinoline and dihydro‐1H‐cyclopenta[c]naphtha[2,3‐h]quinoline moieties have been synthesized by one pot reaction of tetrasubstituted cyclopentadienones with N‐arylamines and formaldehyde in the presence of trifluoroacetic acid. The control of the regioselectivity was total as well with symmetrical and non symmetrical cyclopentadienones. The X‐ray structures of new quinolines were reported.     

Reaction of Dichlorocarbene with Substituted Cyclopentadienones Under Phase Transfer Conditions

The cycloaddition reactions involving dichlorocarbene generated under phase transfer conditions have been studied extensively in the past few years due to the simplicity of the procedure involved.¹ The facile formation of dichlorocyclopropanes provides an easy entry to functionalised aromatics and expanded carbocyclic compounds.² The dichlorocarbene generated under phase transfer conditions is capable of adding even to electron deficient olefins. We describe here the cyclo-addition reaction of dichlorocarbene to tetrasubstituted cyclopentadienones.     

Cyclopentadienones as intermediates for the synthesis of highly functionalized biaryls

A new approach to the synthesis of substituted biaryls, via Diels-Alder reaction between cyclopentadienones and arylacetylenes, is described.     

基于环戊二烯酮结构的新型交替共聚物的合成及性能

以3,4-乙撑二氧噻吩(EDOT)为电子给体单元、烷基链取代的四苯基环戊二烯酮分子为电子受体单元,采用Stille偶联法合成了一种新型的低能带隙交替共聚物(DPPD)。利用核磁共振(NMR)、紫外-可见光谱(UV-Vis)、凝胶渗透色谱(GPC)、循环伏安(CV)、热重分析(TGA)、示差量热分析(DSC)等对共聚物进行了表征。结果表明:共聚物具有良好的溶解性和热稳定性,热分解温度为376.6℃,数均分子量为1.45×104,分子量分布为1.13,光学能带隙约为1.55 eV,500~750 nm有较宽的吸收。以共聚物DPPD和富勒烯C60衍生物[6,6]-苯基-C61丁酸甲酯(PC60BM)制备的本体异质结器件开路电压为0.63 V,短路电流为0.45 mA/cm2,填充因子为0.28,能量转换效率为0.08%。     

The Reactions of Hexafluorocyclotriphosphazene with Sodium Phenoxide

The reaction of N₃P₃F₆ ( 2 ) with NaOPh led to the phenoxyfluorocyclotriphosphazenes N₃P₃(OPh)_nF_6‐n (n = 1( 3 ), 2( 4 ), 3( 5 )). Structures were assigned using ³¹P decoupled ¹⁹F NMR spectroscopy. The reaction followed a non‐geminal pathway with a 50.7:49.3 cis:trans ratio for 4 and a 28.6:71.4 cis:trans ratio for 5 . Comparisons to the analogous reaction of N₃P₃Cl₆ ( 1 ) were facilitated by DFT calculations on N₃P₃(OPh)X₅ (X = F, Cl) which show that the NBO charges on the phenyl group are invariant with respect to the identity of the phosphazene. These observations have been correlated to mechanistic models for cyclophosphazene substitution reactions.     

三氯乙酸酯与二级胺反应的研究

三氯乙酸酯与二级胺反应,在不同条件下得到不同的产物。当三氯乙酸酯与环状二级胺反应时,碳碳键断裂并生成胺基甲酸酯;而与链状二级胺反应时则发生碳氧键断裂并生成叔胺。     

The Cycloaddition Reactions of Furan with Cyanoacetylenes

The temperature-dependent adduct formation has been reported on the cycloaddition reactions of furan and dimethylacatyledicarboxylate as symmetrically substituted acetylene, in which the kinetically controlled products I and II are formed at room temperature, whereas the thermodynamically controlled ones, III, IV, and V, are obtained at elevated temperature.¹     

The Reactions of Hydridophosphorane with Vilsmeier Reagents

Reactions of hydridophosphorane 3 with Vilsmeier reagents, HCONR¹R²/POCl₃, afford novel N,N-disubstituted amino bisphosphoranyl methanes 4 . The formation of 4 might occur via the intermediate 5 , which then reacts further with excess 3 . © 1997 John Wiley & Sons, Inc. Heteroatom Chem 8 : 517–520, 1997     

秦皮甲素、秦皮乙素与血清白蛋白的相互作用

用荧光光谱法研究了中药有效成分秦皮甲素、秦皮乙素与牛血清白蛋白(BSA)、人血清白蛋白(HSA)的相互作用。结果表明：秦皮甲素、秦皮乙素对血清白蛋白的荧光有较强的猝灭作用,其荧光猝灭为单一的静态猝灭过程,其作用机制属能量转移机制。求得不同温度下反应的结合常数K。由反应焓变、熵变确定它们间的结合主要是静电引力。依据非辐射能量转移机理,求出了其结合位置和能量转移效率。     

The Cyclization Reactions of Lawesson''''s Reagent with Bifunctional Substrates

2,4-Bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-d,common1yknoWnaSLawesson'sreagent(LR),isnotonlythethiatingagentfordiversecarbonylcomPounds'-',butalsoundergoesring-closurereactionswithtWofunctionalgroupstogivephosphorusheterocycleswhichcontalnthe4-methoXyPhenylphosphonothioylienemoiety.Theseheterocycliccompoundsareofpotentialinterestasherbicides,insecticidesandfungicides".Inthebifunctionalsysteminwhichthesubstraesarelocatedl,2orl,3toeachother,theopportUnityexiStsforring-closurerea…     

The Reactions of Hexachlorocyclotriphosphazatriene with Ligands Including Mercapto Groups

In this work, the reactions of hexachlorocyclotriphosphazatriene (trimer), N ₃ P ₃ Cl ₆ 1, with 2-mercapto-1-methylimidazole (methimazole) 2, 2-mercaptopyrimidine 3, and 2-mercaptopyridine 4 were discussed. Mono- (5) and pentasubstituted (6) phosphazenes were obtained from the reaction of 1 with 2-mercapto-1-methylimidazole. Both mono- (7) and disubstituted geminal (8) phosphazenes were obtained from the reaction of 1 with 2-mercaptopyrimidine. But phoshazene or any phosphorus compound could not be isolated from the reaction of 1 with 2-mercaptopyridine.     

The Biochemical Reactions of Organometallics with Enzymes and Proteins

Most specialists doing organometallic chemistry have little understanding of what modern biochemistry is. On the other hand, most biochemists believe that organometallic chemistry stands much apart from the problems they study. But the real distance, if any, between these magnificent pyramids of modern science is progressively decreasing. Their interaction has given birth to a new branch of science, organometallic biochemistry, the general aspects of which are discussed here.     

The Reactions of Dialkyl Phosphites and Phosphine Oxides with Iodosylbenzene

The reaction of iodosylbenzene with >P(O)H type of acids (dialkyl phosphites, secondary phosphine oxides) was studied. The acids of >P(O)H type add to iodosylbenzene to yield intermediate 6 which in the aprotic solvents yields oxidation products, it means >P(O)OH acids and/or anhydride of >P(O)OP(O)< type. On the other hand if the reaction is performed in alcohol as a solvent in the presence of sodium alcoholate >P(O)OR ester is the major product.     

Reactions of Ketene Acetals V The Reaction with p-Benzoquinone Dihalides

2- or 3-Halonaphthoquinones are known to react with ketene dialkyl acetals and to yield 1,3-dialkoxyanthraquinones^2,3. Various p-benzoquinones on the other hand have given only 2-alkoxy-benzofurans². 3-Chloro-5,7-dimethoxy-1,4-naphthoquinone (4) and 1,3,6,8-tetramethoxyanthraquinone (10), important intermediates for the synthesis of naturally occurring quinones, have now been obtained under analogous conditions using p-benzoquinone dihalides (trans-5,6-dihalo 2-cyclohexene 1,4-diones). Compound 4 does not appear to have been described but is readily converted to 3,5,7-trimethoxy-1,4-naphthoquinone (7) and regiospecifically³ to 1,3,6,8-tetramethoxyanthraquinone. Although the yields obtained in the reactions of ketene acetals with quinone dihalides are low, compounds 7 and 10 have only been prepared until now by tedious means involving a large number of steps^4–8, or by the degradation of natural products^9,10.     

The Reactivity of Diphenyl Carbonyl Oxide in Reactions with Alcohols

The reactivities of ten alcohols in the reactions with diphenyl carbonyl oxide Ph₂COO is characterized by the ratio k ^OH ₃₃ /k ₃₁, where k ^OH ₃₃ and k ₃₁are the rate constants of Ph₂COO reactions with an alcohol and diphenyldiazomethane PH₂CN₂, respectively. The values of k ^OH ₃₃ /k ₃₁range between 0.6 × 10^–2for MeOH to 6.0 for iso-PrOH at 70°C in acetonitrile. The donation of electron density to the alcohol hydroxyl group favors the attack of Ph₂COO; that is, Ph₂COO reacts as an electrophile.