Delie An

Synthesis and structure of air-stable Lewis acidic binuclear complex of zirconocene pentafluorophenylsulfonate and its catalytic application in the allylation of carbonyl compounds with tetraallyltin.

Air-stable Lewis acidic micro2-hydroxy bridged binuclear complex of zirconocene pentafluorophenylsulfonate was successfully synthesized and found to show high catalytic efficiency in chemoselective allylation of carbonyl compounds with tetraallyltin in aqueous methanol media.

Sulfoximine Version of Double Elimination Protocol for Synthesis of Chiral Acetylenic Cyclophanes

A new strategy for constructing enantiopure acetylenic cyclophanes is described on the basis of one-pot double elimination reaction starting from dialdehydes and bis(sulfoximine)s. In this case, the conventional sulfone protocol affords poorer yields of the desired cyclophanes. Thus, arylene-ethynylene moieties with terminal sulfoximine or formyl functions are linked to binaphthyl cores and these building blocks are then subjected to double elimination reaction. The desired macrocycles are obtained in up to 35 % yield. The corresponding Sonogashira coupling fails to afford cyclophanes indicative of effectiveness of the double elimination methodology.

Synthesis and Structure of an Extremely Air‐Stable Binuclear Hafnocene Perfluorooctanesulfonate Complex and Its Use in Lewis Acid‐Catalyzed Reactions

Stable complexes: An extremely air-stable mu(2)-hydroxy-bridged binuclear hafonocene perfluorooctanesulfoante complex shows high catalytic efficiency in Lewis acid-catalyzed reactions, such as esterification, Friedel-Crafts acylation, the Mukaiyama aldol reation, and the allylation of aldehyde (see scheme).An extremely air-stable mu(2)-hydroxy-bridged binuclear hafonocene perfluorooctanesulfoante complex was successfully synthesized. This complex showed high catalytic efficiency in the esterification of alcohols, phenol, thiol, and amines, in the Friedel-Crafts acylation of alylaryl ethers, in the Mukaiyama aldol reaction, and in the allylation of aldehydes and could be reused.

2,4-Di-t-butyl-6-methoxyphenyldithioxophosphorane as a probe for the mechanistic studies of Lawesson's reagent

Abstract The chemical conversion of carbonyl to thiocarbonyl compound was directly achieved by the treatment of benzophenone with 2,4-di-t-butyl-6-methoxyphenyldithioxophosphorane, which was prepared by the thermolysis of the corresponding dimeric species, 1,3,2,4-dithiadiphosphetane 2,4-disulfides.

Anti-inflammatory effects of novel sinomenine derivatives.

Sinomenine is an isoquinoline-type alkaloid found in Sinomenium acutum (Thunb.) Rehd. et Wils and S. acutum (Thunb.) Rehd. et Wils var. cinereum Rehd. et Wils. When used as a medicine, this compound exhibits anti-inflammatory properties; however, sinomenines use as a medication is limited by side effects, a short half-life, and low efficacy. Owing to these limits, attempts have been made to synthesize sinomenine derivatives with enhanced efficacy. In this study, the anti-inflammatory effects of novel sinomenine derivatives (S1a-S1f) were examined on the basis of lipopolysaccharide-induced inflammatory factor expression in Raw264.7 cells, dimethylbenzene-induced ear oedema, and Evans blue leakage in mice, and carrageenan-induced paw oedema in rats. Compared with sinomenine, the derivatives significantly inhibited the expression of the inflammatory factors IL-1β and IL-6 at the transcriptional and translational levels. Topical application of 3.250mg/kg of the derivatives also alleviated ear oedema. Compared with the vehicle, the derivatives significantly inhibited carrageenan-induced rat paw oedema after 6h. Among the derivatives, S1a exhibited the most potent anti-inflammatory activity. S1a also significantly increased the sinomenine-induced inhibition of Evans blue leakage. Thus, S1a may elicit the strongest anti-inflammatory effects of the tested compounds. Based on these results, further development of this compound may be warranted.

Reactions of (THF) W(CO)5 with some diphosphenes carrying bulky aryl and phenoxy groups

Abstract The reaction of (THF)W(CO) 5 (THF = tetrahydrofuran) with asymmetrical diphosphenes carrying bulky aryl and phenoxy groups gave end-on-type complexes on either phosphorus atom. One of the complexes was analyzed by X-ray crystallography indicating that the major complex suffers less from the steric bulk.

Photoredox catalyst-mediated direct regioselective phosphonylation of indoles

ABSTRACT An efficient hetero-cross-dehydrogenative-coupling (hetero-CDC) reaction between N-protected indoles and phosphites to 2-indolyphosphites is described. The regioselective methodology took place in the presence of photo redox catalyst Ru(bpy)3(PF6)2 combined with oxygen as an clean oxidant when exposed to visible light, furnishing the 2-indolyphosphites as the exclusive products in moderate to good yields with good functional group tolerance. Moreover, the phosphonylation protocol was proved by the control reaction to proceed through the radical pathway. GRAPHICAL ABSTRACT

Copper-Promoted Desulfitative N-Arylation of Sulfonamides and Sulfoximines with Sodium Arylsulfinates

A general and direct N-arylation of sulfonamides and NH-sulfoximines by sodium arylsulfinates through a desulfitative pathway was herein demonstrated. The reaction proceeded with catalytic loadings of Cu(II)-catalysts without any external ligands. And the novel arylation protocol featured for high efficiency (up to 93% yields) and good substituent tolerance (up to 53 examples). Moreover, a plausible reaction mechanism was also discussed.

Efficient One-Pot Preparation of Methylthio Arylbutadiynes by Double Elimination Protocol

Abstract A novel and efficient method for preparation of methylthio arylbutadiynes (Ar-C≡C-C≡C-SCH3) was described, and a series of compounds have been expediently obtained by the one-pot protocol starting from methylthiomethyl phenyl sulfone (MP-S) and arylpropargyl aldehydes. The mechanism was discussed on the basis of trapping and characterization of key intermediates. The results from experiments indicated that the reaction involved the initial nucleophilic addition of MP-S to arylpropargyl aldehydes to produce an intermediate carrying two leaving groups and subsequent double elimination reactions. Supplemental materials are available for this article. Go to the publishers online edition of Synthetic Communications® to view the free supplemental file. GRAPHICAL ABSTRACT

Air-Stable, Cationic, Lewis Acid, Titanocene Perfluorooctanesulfonate–Catalyzed Reductive Cleavage of S–S Bond by Zinc and Its Application in Synthesis of Thioesters

Titanocene perfluorooctanesulfonate is air-stable complex. In the presence of 10 mol% of the complex, reductive cleavage of an S–S bond by zinc in commercial tetrahydrofuran at room temperature led to nucleophilic sulfur anion species, which reacted with acid anhydrides to afford thioesters in good to excellent yields.