Rhodium(II) acetate-catalyzed reaction of 2-amino-4,5-dihydro-3-furancarbonitriles with dialkyl diazomalonates

2-Amino-4,5-dihydro-3-furancarbonitriles 3 react with dialkyl diazomalonates in the presence of rhodium(II) acetate to yield dialkyl (5-amino-4-cyano-2,3-dihydro-3-furanyl)propanedioates 4 . Dehydrogenation of 4 with DDQ provided dialkyl (5-amino-4-cyano-3-furanyl)propanedioates 5 .     

Stereoselective synthesis of substituted arylsulfonylated 1,3-butadienes and 2-propenoates by sulfonylation of acetylenic ester

Protonation of the reactive intermediates produced in the reaction between sodium arylsulfinates and two equiv. of dialkyl acetylenedicarboxylates in DMF, by H₂O lead to substituted (1E,3E)-1-(arylsulfonyl)-1,3-butadiene-1,2,3,4-tetracarboxylates in moderate yields. A regioselective method for the synthesis of alkyl (E)-3-(arylsulfonyl)-2-propenoates is described. These reactions provide a useful synthetic route to highly functionalized 1,3-butadienes and 2-propenoates.     

α-苯乙胺拆分2-取代丁二酸1-叔丁酯

在乙酸乙酯中,对2-取代丁二酸1-叔丁酯和手性α-苯乙胺形成的非对映体盐进行化学拆分,得到了(R)-和(S)-2-取代丁二酸1-叔丁酯.     

Ferrocenyl(dimethyl)aluminum dimer [(η5-C5H5)Fe(η5-C5H4)AlMe2]2

The reaction of ferrocenyllithium (FcLi, 1) with dimethyl or diethylaluminum chloride affords known mixed dimers 2 built from dialkyl(ferrocenyl))aluminium and dialkylaluminum chloride and also, depending on the reaction conditions, the unknown dimers from dialkyl(ferrocenyl)aluminum 3, of which the dimethyl derivative could be isolated in a pure state and characterised by X-ray structural analysis. The ferrocenyl group occupies the bridging position and there is a centre of inversion. The solution-state structures were determined by NMR spectroscopic methods (¹H, ¹³C, ²⁷Al NMR). The gas-phase structure of monomer FcAlH₂ 3(M) was optimised at the B3LYP/6-311 + G(d,p) level of theory.     

Synthesis of highly functionalized 9,10-anthraquinones

The reaction of dialkyl acetylenedicarboxylates with ethyl 9,10-dihydro-2-methyl-9,10-dioxo-anthracen-1-yl-carbamoyl-formate in the presence of triphenylphosphine produces dialkyl 2,5-dihydro-1-(9,10-dihydro-2-methyl-9,10-dioxoanthracen-1-yl)-4-ethoxy-5-oxo-1H-pyrrole-2,3-dicarboxylates in fairly good yields.     

Solubility parameters of poly(di-n-alkyl cyclohexyl-) and poly(di-n-alkyl phenyl itaconates)

Solubility parameters of poly(dicyclohexyl-), poly(diphenyl itaconate) and of the first three members of the poly(dialkyl cyclohexyl-) and poly(dialkyl phenylitaconate) homologous series were determined from limiting viscosity numbers in various solvents and solvent mixtures, differing in structure, polarity and composition. The values obtained are within limits of 19.0 and 16.7 (J^1/2. cm^-3/2). Phenyl groups in the substituents lead to slightly higher values than cyclohexyl rings and the introduction of alkyl groups in both series results in a progressive decrease of the solubility parameter. The experimental values are slightly lower than those obtained by calculation from molar attraction constants.     

Allylic polymers. Diallyl 2-substituted succinate prepolymers and their properties

Diallyl 2-substituted succinates, obtainable via the addition of alkenes or alkylaromatics to maleic anhydride, undergo intramolecular cyclization during polymerization to low molecular weight prepolymers. The amount of this cyclization and the properties of the cured prepolymers are profoundly affected by the structure of these 2-substituents. Thus, the degree of cyclization decreases with these substituents in the order: aralkyl and isobutyl > unhindered alkenyl > alkyl > hindered alkenyl. Properties of thermosetting molding compounds based on these prepolymers are inferior to those of poly-(diallyl phthalate) molding compounds.     

A convenient synthesis of alkyl-2-(2-imino-4-oxothiazolidin-5-ylidene)acetate derivatives involving an electrogenerated base of acetonitrile

We report a simple method for the synthesis of alkyl-2-(2-imino-4-oxothiazolidin-5-ylidene) acetate derivatives 3 in good yields under mild conditions. The electrogenerated cyanomethyl base (EGB), obtained from electroreduction of acetonitrile-0.1?M TBABF₄, assists the reaction between thiourea derivatives 1 and dialkyl acetylene dicarboxylate 2. The expected products, 3/4, and the structure obtained from X-ray diffraction confirm that the main products are the five-membered heterocycles 3. Furthermore, a mechanism, to explain the reaction pathways, is proposed based on the thermodynamic and kinetic data obtained from quantum calculations.     

Efficient synthesis of functionalized bis-(4-oxo-1,3-thiazolan-5-ylidene)acetates

Reaction of 1-(2,2-dimethyl-propionyl)-3-{4-[3-(2,2-dimethyl-propionyl)thioureido]phenyl}thiourea or 1-(2,2-dimethyl-propionyl)-3-{5-[3-(2,2-dimethyl-propionyl)thioureido]naphthalen-1-yl}thiourea with dialkyl acetylenedicarboxylates in CH₂Cl₂ leads to alkyl (2-(2,2-dimethyl-propionylimino)-3-{4-[-(,2-dimethyl-propionylimino)-5-alkoxycarbonylmethylene-4-oxo-thiazolidin-3-yl]-phenyl}-4- oxo-thiazolidin-5-ylidene)acetates or alkyl (2-(2,2-dimethyl-propionylimino)-3-{5-[2-(2,2-dimethyl-propionylimino)-5-alkoxycarbonylmethylene-4-oxo-thiazolidin-3-yl]naphthalen-1-yl}-4-oxo-thiazo lidin-5-ylidene)acetates in good yields.     

Organophosphorus chemistry. 13 [1]. The Behaviour of 3-Aryliminoxindoles toward Alkyl Phosphites

3-Aryliminoxindoles ( 6a–c ) react with trialkyl phosphites (TAP, 2a–c ) only in presence of a protonating agent (H₂O or CH₃COOH) to give the respective dialkyl 3-(arylamino-2-oxo-1H-indol-3-yl)-phosphonates ( 9a–i ). Compounds 9 are equally obtained by reacting 6a–c with the appropriate dialkyl phosphite (DAP, 4a–c ) in absence of solvent. The role displayed by the arylimine-moiety on the reaction courses is discussed. A mechanism that accounts for formation of 9 from the reaction of anils 6 with TAP, is presented. Structural assignment are based upon analytical, chemical and spectroscopic (i.r., ¹H-n.m.r., ³¹P-n.m.r. and m.s.) results.     

Preparation and plasticizing characteristics of a series of symmetrical and unsymmetrical N,N-Disubstituted oleamides

Thirty-five N,N-disubstituted oleamides, mostly dialkyl oleamides, have been prepared and evaluated as plasticizers for vinyl chloride-vinyl acetate copolymer to investigate the relative effect upon plasticizer performance of N,N-symmetrical and unsymmetrical substitution; groups such as alkyl, cycloalkyl, benzyl, 2-alkoxyethyl, 2-acetoxyethyl, 2-(3-carbobutoxypropionlyoxy)ethyl, 2-(3-carbohexanoxypropionyloxy)ethyl, and cyanoethyl have been investigated in systematic combinations. The compatibility of symmetrical or unsymmetrical N,N-dialkyl oleamides, involving normal, branched, or cyclic alkyls, is controlled by the total carbon count of the combined substituent groups rather than that of the larger group. For retention of compatibility the total carbon count must not exceed about 13 atoms. Symmetrical and unsymmetrical dialkyl oleamides of the same total alkyl carbon count do not differ significantly in their plasticizing characteristics. Acyclic N,N-dialkyl oleamides are, with few exceptions, highly efficient plasticizers, which impart good, sebacate-like, low-temperature impact performance to the plastic composition. A substituent attached to the nitrogen through a secondary carbon severely impairs plasticizer efficiency and cyclic or cycloalkyl substituents are detrimental to low-temperature performance. Substitution of an alkyl group for one of the N,N-disymmetrical substituents has little or no effect upon low-temperature impact performance. Many of the disubstituted oleamides impart antistatic properties to the plastic composition.     

Simple and green method for synthesis of symmetrical dialkyl disulfides and trisulfides from alkyl halides in water; PMOxT as a sulfur donor

An environmentally new, mild and efficient method has been developed for the synthesis of dialkyl disulfides and dialkyl trisulfides in aqueous conditions by a reaction between alkyl halides (and tosylate) and potassium-5-methyl-1,3,4-oxadiazole-2-thiolate (PMOxT) as a sulfur transfer reagent. The advantages of this method are that it occurs under mild reaction conditions, it is base free, it uses water as the solvent and it occurs in high yields. A variety of dialkyl disulfides and dialkyl trisulfides can be obtained in good to excellent yields up to 98%.     

The fire-resistance properties of polycarbonates

Summary The present paper describes two types of polycarbonates possessing fire-resistance. The first type is obtained by reacting dialkyl bis(hydroxy-4-phenyl) alkyl phosphonates with phosgene and the second type is a copolymer of bisphenol A and dialkyl bisphenol phosphonates.We show that the incorporation of dialkyl bisphenol phosphonates into the bisphenol A polycarbonate chains can be satisfactorily carried out using interfacial polycondensation.The products with groups-P (OCH₃)₂ possess high oxygen indices (OI).     

O-乙基-O-(2-甲酰基苯基)-N-(1-甲基乙基)硫代磷酰胺酯的制备及其氨解反应

在研究了水杨醛与O 乙基硫代磷酰二氯反应的基础上 ,首次报道了O 乙基 O (2 甲酰基苯基 ) N (1 甲基乙基 )硫代磷酰胺酯的合成 ,同时发现该标题化合物的氨解反应 ,给出了尚未见文献报道的O (2 甲酰基苯基 ) N ,N′ 二烷基硫代磷酰胺酯类化合物     

Elektrosynthese von O,O-Dialkyl-vinylphosphonaten

Electrosynthesis of O,O-Dialkyl Vinylphosphonates A new procedure for the preparation of dialkyl 2,2-dichlorvinylphosphonates 2 , dialkyl 2,2,2,1-tetrachlorethylphosphonates 3 and dialkyl 2,2,1-trichlorvinylphosphonates 4 is described. The polarographic behaviour and some physical properties of these compounds are reported.     

高碳脂肪醇磷酸酯合成的~(31)P-NMR波谱研究

采用 3 1　P NMR波谱对高碳脂肪醇与五氧化二磷的反应进行了研究 ,定量地表征了产物混合物中的各组分。结果表明 :单酯 (MAP)、双酯 (DAP)、聚酯 (PAP)和磷酸盐 (PA)在 3 1　P NMR波谱上的化学位移分别为 :3 5～ 4 6 ,0 8～ 1 1,- 9 0～ - 10 0和 3 0～ 3 5 (当pH =9时 )。同时为不同用途的脂肪醇磷酸酯盐提供了可选择的和稳定的合成条件 ,即 :在n(ROH)∶n(P2 O5) =(2 3∶1 0 )～ (3 1∶1 0 ) ,反应时间 2～ 3h ,反应温度不大于 10 0℃条件下 ,P2 O5的转化率大于 95 % ,MAP、DAP和PAP的选择性分别为 4 0 %～ 6 5 % ,2 5 %～ 33%和 10 %～ 30 %。     

SO_4~(2-)/TiO_2固体酸负载BINOL催化膦氢化反应

将SO_4~(2-)型固体酸SO_4~(2-)/TiO_2的Lewis酸性位点与BINOL的Brnsted酸性位点进行负载,制备出具有较强双氢键供体的BINOL负载的SO_4~(2-)/TiO_2催化剂。以不同取代基团的芳香族伯胺和肉桂醛缩合制备的芳香族亚胺为催化底物,在10 mol%BINOL负载的SO_4~(2-)/TiO_2催化剂的催化作用下,与亚磷酸二烷基酯(亲核试剂)进行膦氢化反应。同时,通过对比固体酸SO_4~(2-)/TiO_2、BINOL、BINOL负载的SO_4~(2-)/TiO_2催化剂的催化活性,从而对BINOL负载的SO_4~(2-)/TiO_2催化剂进行客观地评价。另外,在较优的催化条件下,以BINOL负载的SO_4~(2-)/TiO_2为催化剂,成功地合成了α-氨基膦酸酯类衍生物,且产率可达80%~88%。另外,基于氢键的作用模式,提出了适合于膦氢化反应较为合理的作用机理。     

An efficient synthesis of stable sulfur-containing phosphoranes derived from 2-mercapto-1-methylimidazole and 2-thiazoline-2-thiol

Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of strong SH-acids, such as 2-mercapto-1-methylimidazole and 2-thiazoline-2-thiol. These stable ylides exist in solution as a mixture of two geometrical isomers as a result of restricted rotation around the carbon–carbon partial double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group.     

STUDIES ON THE STRUCTURAL EFFECT OF DIALKY (ARYL) SULFIDES IN GOLD AND PALLADIUM EXTRACTION

A systematic study of the structural effects of dialkyl(aryl) sulfides on the extraction equilibra of Au (III) and Pd (II) are reported. Dialkylsulfides are excellent extractants with high capacities and selectivity for Au and Pd from HC1 solution. The extraction behavior of dialkyl(aryl)sulfides may be controlled by polar and steric substituents effect. The distribution data suggested that the extracted species were AuCl₃ R₂S and PdCl₂SUB 2R₂S, respectively.     

Synthesis of Multifunctional 3‐Amino‐4‐phosphono‐2‐quinolinones via Regioselective Ring Enlargement of Imino Isatins

Multifunctional 3‐amino‐4‐dialkylphosphono‐2‐quinolinones have been prepared by “one‐pot” nucleophilic addition and regioselective ring enlargement of imino isatins. The addition reaction between imino isatins and dialkyl (diazomethyl)phosphonate proceeds smoothly using potassium carbonate as a catalyst, and a subsequent regioselective ring expansion promotes by salicylic acid to afford the desired products in high yields.