Synthesis of new benzo[b]thieno fused ring systems via transition metal-mediated cyclisations

The compact synthesis of a new ring fused benzo[b]thieno derivative with an embedded nine-membered ring system via ring closing metathesis methodology is described. The preparation of the novel 11H-benzo[b]thieno[2,3-c]pyrrolo[2,3-a]indol-11-one via palladium-mediated oxidative cyclisation of benzo[b]thien-2-oyl indole derivatives is also reported.     

Synthesis of Selenolo(2,3-b)quinoline-2-carboxylic Ethyl Esters: Cytogenetic Studies on Human Peripheral Blood Leucocyte Cultures,and Anti-Bacterial Studies,and Anti-Fungal Studies of Their Effects

The compounds selenolo(2,3-b)quinoline-2-carboxylic ethyl esters were synthesized in good yields by the reaction of 3-(2-chloro-3-quinolyl)acrylic ethyl esters, with the nucleophilic reagent sodium diselenide in ethanol medium under a nitrogen atmosphere. Cytogenetic studies on human blood leucocytes in vitro were evaluated for some of the synthesized compounds. Most of the synthesized compounds were tested for their antibacterial and antifungal activities.     

TFA-catalysed tandem double cyclisation: A one-pot,metal-free routes for novel indolo-imidazo[1,2-a]pyridine derivatives

A transition-metal free, one-pot tandem synthetic routes for novel indole and imidazo[1,2-a]pyridine derivative hybrids have been established. An efficient three-component reaction was designed with incorporation of two sequential Groebke–Blackburn–Bienayme (GBB) and cyclization reaction in one-pot under mild acidic condition. The salient feature of this protocol is atom economy, good yield and operational simplicity. A molecular prospective library of 32 compounds was synthesized by utilizing the various substituted aryl aldehydes and 2-aminopyridine.     

Trifluoromethylated (tetrahydropyrrolo) quinazolinones by a new three‐component reaction and facile assignment of the regio‐ and stereoisomers formed by NMR spectroscopy

A new three‐component cyclisation reactions of methyl 3,3,3‐trifluoropyruvate, 2‐aminobenzylamine and oxo compounds afforded tetrahydropyrroloquinazolinones of the types 4 and 5 as mixtures of regio‐ and stereoisomers. Whereas standard 1D NMR spectroscopy was used for a facile assignment of the cyclization regioisomers, a combination of homo (proton–proton) and heteronuclear (proton–fluorine) NOE experiments allowed the determination of the relative configuration on stereogenic centres. The structure of some compounds was also confirmed by the X‐ray diffraction. Adaptation of the 1D double‐pulsed field‐gradient spin‐echo NOE for a heteronuclear case is presented. Copyright © 2010 John Wiley & Sons, Ltd.     

Heck-like coupling and Pictet-Spengler reaction for the synthesis of benzothieno[3,2-c]quinolines

A series of 6-arylbenzothieno[3,2-c]quinolines were synthesised in three steps from benzo[b]thiophene. After a selective Heck-type coupling of benzo[b]thiophene with different o-nitroaryl bromides to obtain 2-(o-nitroaryl)benzo[b]thiophenes, corresponding 2-(benzo[b]thiophen-2-yl)anilines were involved in a Pictet-Spengler reaction to form the quinoline cycle.     

α-羰基烯酮二硫代缩醛化学的进展

本文综述了α-羰基烯酮二硫代缩醛化学的最新进展, 包括其制备、反应及其在有机合成中的应用。     

Synthesis and alkylation of indolo[3,2-b]carbazoles

Double Fischer cyclisation was used to prepare indolo[3,2-b]carbazole and its 2,8-di-OMe, OH, Br and F-derivatives. N-monosubstituted derivatives of indolo[3,2-b]carbazole (methyl, hydroxymethyl, dimethylaminoethyl) were obtained starting from 5,11-di-Boc-indolo[3,2-b]carbazole.     

The enantiospecific synthesis of chromanes and isochromanes using a variant of an intramolecular Nicholas reaction

The enantiospecific synthesis of chromanes and isochromanes obtained from an intramolecular Nicholas cyclisation reaction is discussed. During the course of this study we observed the formation of chroman-4-ones from a CAN deprotection step of a dioxolane and this is also discussed.     

Oxidation during reductive cyclisations using Bu3SnH

Reductive cyclisations using Bu₃SnH include an “oxidation” step if the removal of an acidic proton from the intermediate cyclised radical, by Bu₃SnH acting as a base, is favourable. A “pseudo” S_RN1 mechanism is proposed.