A novel protocol for the copper-catalysed S-arylation of thiophenol derivatives with aryl halides leading to diaryl sulfides is reported. The reactions were catalysed by a combination copper salt and 1,2-diamine derivative (acting both as ligand base) using exclusively water solvent. recovery successful reutilisation aqueous medium containing active catalyst described. Furthermore, one example "one-pot" process involving Br/I exchange an bromide further presented.

Triptycylhelicenes 1 and 2 were examined as molecular rachets (see picture) in which the triptycene serves rachet wheel (a) helicenes pawl (b) spring (c). The ease of rotation depends on helicene springs pawls, but do these have any influence direction rotation?

A more sustainable protocol leading to 2-alkyl- or 2-aryl-substituted benzo[b]furans is reported, involving a copper−TMEDA complex which catalyzes the transformation of readily available ketone derivatives into corresponding benzofurans in good excellent yields. The reaction accomplished using water as solvent without organic cosolvents, and one example catalyst reutilization also presented.

The triptycene-substituted [3]- and [4]helicenes 1 2 were examined as possible molecular versions of mechanical ratchets, where the triptycene serves ratchet wheel helicenes pawl spring. syntheses 2b are described. 1H NMR was employed to examine rotation around triptycene/helicene single bond; at 20 °C is frozen for both 2b, but revealed a plane symmetry, indicating that cannot function unidirectional ratchet. In contrast, that, like ratchet, triptycyl[4]helicene lacks symmetry has barrier...

A novel approach to the synthesis of indoline derivatives is presented. The key cyclization step features phenyliodine(III) bis(trifluoroacetate)- (PIFA-) mediated formation a N-acylnitrenium ion and its succeeding intramolecular trapping by olefin fragment. In addition, difunctionalization alkene moiety achieved since in situ generation an additional hydroxy group at terminal position original double bond accompanies C−N formation.

Abstract The Suzuki biaryl coupling of a range electronically dissimilar arylboronic acids and aryl bromides is performed in neat water with excellent to quantitative yields by means new CNC‐pincer palladium catalyst that soluble due its para ‐carboxy group. Extremely high turnover numbers frequencies combined remarkable robustness allow an effective reuse sustainable conditions.

The hypervalent iodine reagent PIFA promotes the intramolecular electrophilic cyclization of easily accessible alkynylamides and alkynyl carboxylic acids, leading to formation pyrrolidinone lactone skeletons, respectively, in a very efficient way. A synthetic study mechanistic proposal for these transformations are presented.

The synthesis of a series N,N'-disubstituted indazolone derivatives starting from methyl anthranilates is presented. This general approach features novel and easy way for access to the target N-heterocycles by formation new N-N single bond. key cyclization step embraces an N-acylnitrenium intermediate, mediated hypervalent iodine reagent PIFA, its succeeding intramolecular trapping amine moiety under rather mild experimental conditions.

[reaction: see text] The synthesis of a series benzisothiazolone derivatives starting from the readily available methyl thiosalicylate is presented. key cyclization step features formation N-acylnitrenium ion, generated by hypervalent iodine reagent PIFA, and its succeeding intramolecular trapping thiole moiety leading to construction title compounds new N-S bond.

A convergent total synthesis of the anti-HIV michellamines (1) is described. The tetraaryl skeleton was constructed by formation first inner (nonstereogenic) biaryl axis and subsequently two other (stereogenic) axes in a highly manner. key transformation features double Suzuki-type cross-coupling reaction between binaphthalene ditriflate 26 isoquinolineboronic acid 35. Ditriflate synthesized six steps starting from diene 6 2,6-dibromobenzoquinone (9) 21% overall yield. For large scale...

[reaction: see text] A novel metal-free approach to the alkyne amidation reaction is presented. The oxidation of properly substituted amides by hypervalent iodine reagent PIFA provides generation a nitrenium ion that can react intramolecularly with triple bond, leading construction title compounds.

The synthesis of a series optically pure benzo-, naphtho-, and heterocycle-fused pyrrolo[2,1-c][1,4]-diazepin-5,11-dione derivatives starting from l-proline methyl ester is presented. synthetic plan includes an aroylation step at the proline nitrogen followed by transformation residue into N-methoxyamide group. subsequent key cyclization embraces PIFA mediated formation N-acylnitrenium intermediate its succeeding intramolecular trapping aromatic ring. presented general approach solves need...

Direct oxidation of suitably functionalized amides by application the hypervalent iodine reagent PIFA [bis(trifluoroacet­oxy)iodo]benzene allows straightforward access to a variety nitrogen-containing heterocycles. Comprehensive results from our group on scope and limitations such transformations will be highlighted. 1 Introduction 2 PIFA-Mediated Electrophilic Aromatic Amidation 3 Olefin 4 Alkyne 5 N–N N–S Bond Formation 6 Synthetic Applications Heterocyclization Reactions 6.1 Synthesis...

A new route to oxcarbazepine (Trileptal), the most widely prescribed antiepileptic drug, starting from commercially available 2'-aminoacetophenone and 1,2-dibromobenzene, is reported. The sequentially accomplished key steps are palladium-catalyzed intermolecular α-arylation of ketone enolates intramolecular N-arylation reactions. After several experiments establish best conditions for both arylation processes, target obtained in a satisfactory overall yield, minimizing number employing...

Abstract The synthesis of a series 2,3‐diarylbenzo[ b ]furans starting from 1,2‐diarylethanones and 1,2‐dibromoarenes proceeds by means both homogeneous polymer‐anchored palladium catalysts. This tandem process can be effectively halted at the C ‐arylation step, thus providing key o ‐bromoarylated deoxybenzoin intermediates in good yields. efficient oxidative coupling leading to benzo[ ]phenanthro[9,10‐ d is carried out using safer hypervalent iodine reagent PIFA. (© Wiley‐VCH Verlag GmbH...

After a rigorous study on the effect of several catalytic systems, simple, high yielding procedure for preparation 1,2,2-triarylethanones, skeletal analogues tamoxifen, is presented. Apart from economic and environmental advantages involved, this palladium-catalyzed arylation deoxybenzoin enolates features lack ortho-arylation side reactions. In addition, an alternative approach acetophenones to target triarylethanone system also announced.

Novel dibenzo[a,c]phenanthridines are prepared regioselectively by the application of a straightforward synthetic pathway, starting from new 3,4-diaryl- and 3,4-dihydro-3,4-diarylisoquinolines via Ritter-type heterocyclization more classical two-step reductive amination/Bischler-Napieralski cyclization triarylethanones, respectively. A comparative study nonphenolic oxidative coupling methodologies provides highly efficient procedure, based on hypervalent iodine reagent phenyliodine(III)...

Mit Triptycen als Zahnrad (a) und der Heliceneinheit Sperrklinke (b) Feder (c) wurden die „molekularen Sperräder”︁ 1 2 entworfen. Daß Leichtigkeit Drehung des Triptycen‐Zahnrads von den Helicen‐Klinken ‐Federn abhängt, ist augenfällig, haben diese aber auch einen Einfluß auf Drehrichtung? magnified image