Access to Polycyclic Derivatives by Triflate‐Catalyzed Intramolecular Hydroarylation

Abstract

An efficient and versatile synthesis of indane, tetralin and benzosuberan derivatives has been developed; the synthesis starts from nonactivated aromatic compounds bearing unsaturated side chains and is a bismuth(III) or indium(III) trifluoromethanesulfonate‐catalysed atom‐economic process. A variety of polycyclic compounds have been isolated in high yields. Lactonisation could be observed for esters with 2,2‐disubstituted terminal olefins through a Lewis acid catalysed reaction between the olefin and one of the ester groups.

Solvent‐Free Synthesis of 4H‐Pyrido[1,2‐a]pyrimidin‐4‐ones Catalyzed by BiCl3: A Green Route to a Privileged Backbone

“…[11][12][13]. Lowering of the reaction temperature from 100 to 80 and 50°C led to a reduction in yield to 75 and 52 %, respectively (Table 1, Entries 13-15).…”

“…Bismuth catalysis has gained attention over the past decade due to an increasing focus on green chemistry. [12] Although bismuth is a heavy metal, it is not carcinogenic. [13] Bismuth salts are nontoxic and are, in fact, rated with lower toxicity than even NaCl.…”

Cyclisation Reactions Involving Alkyl Enol Ethers

“…The implementation of new catalytic methodologies for the construction of cyclic scaffolds by electrophilic activation of (poly)unsaturated precursors has been a longstanding interest of the community and intramolecular cyclisations continue to provide efficient and atomeconomic tools for carbo-and heterocycle synthesis. [2] While cyclisations and cycloisomerisations of dienes and enynes are well documented, [3] the introduction of oxygen-functionality into the precursor molecules by means of an enol ether is less explored. Since enol ethers can be considered reactive derivatives of ketones or aldehydes, as well as activated, electron-rich alkenes, they often share common reactivity patterns with their parent structures and undergo similar chemical transformations.…”

Selenide-catalyzed enantioselective synthesis of trifluoromethylthiolated tetrahydronaphthalenes by merging desymmetrization and trifluoromethylthiolation

“…In these transformations, the tethered nucleophile played an important role that it could bind a catalyst to guarantee an effective attack toward the multiple bond, which led to the formation of chiral products with high enantioselectivities. In contrast, enantioselective desymmetrization involving the attack of aryl group toward a multiple bond that results in the formation of multisubstituted tetrahydronaphthalene derivatives, an important class of bioactive compounds 44 – 46 , has been far less explored possibly because of the lack of the appropriate interaction between the aryl moiety and catalyst 47 – 49 . Only a few relevant examples have been reported by Chemler who utilized amine- or hydroxy-tethered alkenes for carboamination and etherification through a copper-catalyzed radical pathway (Fig.…”