Some properties of the adduct of benzenesulfinyl chloride with myrcene

Conclusion The reaction of PhSOCl with myrcene at high pressure leads to the cis-1,4 addition product.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5 pp. 1143–1145, May, 1987.     

Rhodium catalysed coupling reaction of myrcene with ethyl acetoacetate in the ionic liquid 1-ethyl-3-methylimidazolium triflimide

The ionic liquid 1-ethyl-3-methylimidazolium triflimide was used successfully as the reaction medium to carry out the rhodium catalysed coupling of myrcene with the active methylene compound ethyl acetoacetate in the presence of TPPMS as the ligand. Coupling product was obtained in 93% isolated yield without any side product formation when a 1:50 ratio of rhodium catalyst/TPPMS was used.     

双戊烯合成萜马加成物的研究

以稀土金周氧化物（盐）为催化剂，催化工业双戊烯与顺丁烯二酸酐连续进行异构／Diels—Aldet反应，合成出萜烯／马来酸加成物；并用气相色谱法跟踪研究了反应的进程，及产物的组成与生产物的结构．结果表明本合成反应条件温和，反应易于控制，催化剂易于回收，产物得率比文献值高20个百分点，产物纯度大于90％，且产物性能能满足进一步合成的要求，为我国工业双成烯的应用开拓了新领域。     

Electrophilic Chlorine from Chlorosulfonium Salts: A Highly Chemoselective Reduction of Sulfoxides

Herein, we describe a selective late-stage deoxygenation of sulfoxides based on a novel application of chlorosulfonium salts and demonstrate a new process using these species generated in situ from sulfoxides as the source of electrophilic chlorine. The use of highly nucleophilic 1,3,5-trimethoxybenzene (TMB) as the reducing agent is described for the first time and applied in the deoxygenation of simple and functionalized sulfoxides. The method is easy to handle, economic, suitable for gram-scale operations, and readily applied for poly-functionalized molecules, as demonstrated with more than 45 examples, including commercial medicines and analogues. We also report the results of competition experiments that define the more reactive sulfoxide and we present a mechanistic proposal based on substrate and product observations.     

A short multigram asymmetric synthesis of prostanoid scaffolds

Enantiomerically pure polysubstituted cyclopentanes which can be regarded as prostanoid scaffolds have been prepared by an efficient synthetic sequence readily applicable to the preparation of multigram quantities. The first key reaction is the diastereoselective allylmetallation of oxoamide 4 which is readily prepared from γ-butyrolactone and an enantiomerically pure 2,5-dimethylpyrrolidine. The second key-step is an intramolecular [2+2] cycloaddition of a keteneiminium salt leading to bicylo[3.2.0] heptanones. These intermediates have been easily transformed into a variety of prostanoid scaffolds of high enantiomeric purities.     

A short synthesis of highly substituted furans from alkenyl aryl ketones with dichloromethyl phenyl sulfoxide

Two-step synthesis of 2-aryl-5-(phenylsulfanyl)furans was achieved starting from alkenyl aryl ketones and dichloromethyl phenyl sulfoxide. The phenylsulfanyl group was successfully converted to other functional groups, via sulfinyl group, to give highly substituted 2-arylfurans in good overall yields.     

A short diastereoselective synthesis of the (±)-rishirilide B core structure

A series of diastereoselective reactions are reported to form the core of (±)-rishirilide B. The key reactions include: (1) a regioselective tautomerization and etherification of an asymmetric cyclohexa-1,3-dione, (2) an alkoxide directed 1,2-addition of an organometallic reagent and carbamate cleavage and protonation sets two stereocenters, and (3) a novel RuO₄ cleavage of an α-hydroxy vinyl ether provides the α-hydroxy ester.     

A four step synthesis of violaceic acid

The total synthesis of the biaryl ether natural product violaceic acid (1) in four steps is described. The steps included a S_NAr reaction between phenol 7 and flouroarene 12 to afford the biaryl ether 13, selective reduction of a nitro group to an amine in the presence of an aldehyde, a Cu mediated Sandmeyer reaction and final hydrolysis to afford the target compound 1. The amine 14 was also converted into the known iodide 18 which gave impure 1 on Pd mediated hydroxide cross coupling.     

Phosphoryl chloride-mediated solvent-free synthesis of N-aryl-substituted azacycles from arylamines and cyclic ethers

A solvent- and metal-free protocol for preparation of N-aryl substituted azacycles from arylamines and cyclic ethers is described. In this method, the combination of POCl₃ and DBU is crucial for conversion of arylamines and cyclic ethers to five- and six-membered azacycles. Without solvent, a variety of N-aryl-substituted, five-membered azacycles (pyrrolidines, 2-methylpyrrolidines, and piperidine) and six-membered azacycles (isoindolines and tetrahydroisoquinolines) are synthesized in high yields. This green method provides a sustainable and efficient approach for the preparation of azacycles from various cyclic ethers.     

A short and concise asymmetric synthesis of hamigeran B

The interesting biological properties of the hamigerans wherein hamigeran B is a potent antiviral agent with low cytotoxicity to host cells make these deceptively simple looking structures challenging synthetic targets. A strategy to hamigeran B evolved wherein the three contiguous stereocenters are established ultimately from a Pd catalyzed asymmetric allylic alkylation (AAA). The latter involves an asymmetric allylation of a non-stabilized ketone enolate in 77 % yield and 93 % ee. By using this process, (S)-5-allyl-2-isopropyl-5-methyl-1-trifluoromethanesulfonyloxycyclopentene becomes available in four steps from 2-methylcyclopentanone. Introduction of the aryl unit by cross-coupling proceeded intermolecularly but failed intramolecularly. On the other hand, reductive removal of the triflate permitted a Heck reaction to effect intramolecular introduction of the aryl ring. The unusual conformational properties of this molecular architecture are revealed by the regioselectivity of the beta-hydrogen elimination in the Heck reaction and the diastereoselectivity of the reduction establishing the stereochemistry of the carbon bearing the isopropyl group. The successful route consists of 15 steps from 2-methylcyclopentanone and dimethylorcinol illustrating the efficiency of the route based upon the Pd AAA.     

A method for the synthesis of stable aryldiazonium salts possessing a 1,1,2,3,3-pentacyanopropenide anion

A method for the synthesis of stable aryldiazonium salts possessing an organic 1,1,2,3,3-pentacyanopropenide anion is reported.     

Novel photocurable monomers: The synthesis of difunctional vinyl ethers with a phosphonate group and difunctional 1‐propenyl ethers with a phosphonate group and their photoinitiated cationic polymerization

Phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were prepared by the regioselective addition reaction of glycidyl vinyl ether (GVE) or 1‐propenyl glycidyl ether with diaryl phosphonates with quaternary onium salts as catalysts. The reaction of GVE with bis(4‐chlorophenyl) phenylphosphonate gave bis[1‐(4‐chlorophenoxy methyl)‐2‐(vinyloxy)ethyl]phenylphosphonate in a 68% yield. The structures of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were confirmed by IR and ¹H NMR spectra and elemental analysis. Photoinitiated cationic polymerizations of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were investigated with photoacid generators. The polymerization of vinyl ether groups and 1‐propenyl ether groups of the obtained monomers proceeded very smoothly with a sulfonium‐type cationic photoinitiator, bis[4‐(diphenylsulfonio)phenyl]sulfide‐bis(hexafluorophosphate), upon UV irradiation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3105–3115, 2005     

Solvent extraction separation of gallium with 18crown6 from chloride media

Gallium was quantitatively extracted with 0.02M 18crown6 in methylene chloride from 6M hydrochloric acid, then stripped with 1M acetic acid and determined with 2-(pyridylazo)naphthol with measurement at 545 nm. Gallium was separated from indium, thallium, lead, aluminium and bismuth. The method was applied to determination of gallium in bauxite.     

Synthesis of methylthiosubstituted heterocycles using the complex of trifluoromethanesulfonic anhydride with dimethyl sulfide

A new method was developed for the electrophilic introduction of methylthio group into a series of aromatic heterocyclic compounds through the hetaryl(dimethyl)sulfonium salts formed in the course of the reaction of the respective heterocycles with the complex of dimethyl sulfide and trifluoromethanesulfonic anhydride. By demethylation with triethylamine it was possible to obtain the methylthio-substituted heterocycles.M. V. Lomonosov Moscow State University. Moscow; e-mail: nen@acylium.chem.msu.ru. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 171–177, February, 2000.     

Michael addition of N-isobutylidene-t-butylamine to dimethyl methoxymethylenemalonate and a new synthesis of some fused pyrazole derivatives from the adduct

N-Isobutylidenemethylamine reacted with dimethyl methoxymethylenemalonate to afford the N-alkylation product 3a exclusively. Exchanging the N-substituent of the Schiff's base from methyl to t-butyl altered the course of the reaction, allowing Michael addition to take place predominantly. The Michael adduct 4c on reaction with hydrazinoalkanols 6a,b, 6c,d and 6e gave tetrahydropyrazolo[5,1-b]oxazoles 9a,b , tetrahydro-pyrazolo[5,1-b][1,3]oxazines 9c,d and hexahydropyrazolo[5,1-b][1,3]oxazepine 9e , respectively.     

简便的"一锅法"合成氟代芳烃

本文采用改进的Schiemann反应, 合成了一些用Schiemann反应不易制得的氟代芳烃。本方法中, 芳烃氟硼酸重氮盐水溶液可不经分离, 室温下"一锅法"反应, 简便合成了对氟硝基苯、对氟苯乙酮, 氟代苯甲酸等, 分离产率为25-62%。