Efficient Intramolecular Hydroarylation Catalysed by Bi^III Triflate

Abstract

Non‐activated aromatic compounds bearing unsaturated side‐chains afford tetralin and benzosuberan derivatives in good yields in an atom‐economic, environmentally friendly process catalysed by bismuth(III) trifluromethanesulfonate.

Catalytic intramolecular carbonyl–ene reaction with ketones: evidence for a retro–ene process

“…42 Compound 1c, bearing a methyl ketone group and a trisubstituted double bond (but on a longer unsaturated side-chain), reacted to afford the bicyclic compound 5c in 47% yield with a 73% conversion (Scheme 7). Thus, the phenyl ketone 1b was reacted according to Scheme 6, to afford compounds 4b and 5b in 74% overall yield.…”

Access to Polycyclic Derivatives by Triflate‐Catalyzed Intramolecular Hydroarylation

“…[19] We published a preliminary report dealing with a Bi III intramolecular cycloisomerisation reaction of aromatic compounds bearing side-chain olefin substituents. [20] We report here that Bi(OTf) 3 or In(OTf) 3 are efficient catalysts for the intramolecular hydroarylation of nonactivated aromatic rings bearing highly substituted olefins in a completely atom-economic process. This eco-friendly methodology constitutes a direct and easy access to indane, tetralin, benzosuberan and other polycyclic derivatives.…”

Catalytic Activation of Olefins by Metal Triflates and Triflimides: Application to Fragrance Chemistry

“…50 Tests with several catalytic systems indicate that Bi(OTf) 3 , used at only 1 mol %, is the most active catalyst for the cyclisation of these unsaturated phenyl derivatives (Scheme ). For the catalytic activity of Bi III derivatives, the nature of the counterion plays an important role and the observed order of reactivity is: OTf>NTf 2 ≫Br≈Cl≈I≈OAc 50. Various Bi(OTf) 3 salts with different solvation also indicate different activities, which follow the order : Bi(OTf) 3 ⋅4 H 2 O>Bi(OTf) 3 ⋅MeCN>Bi(OTf) 3 ⋅7 DMSO.…”

“…Interestingly, the Bi(OTf) 3 ⋅4 H 2 O‐catalysed hydroarylation is highly catalytic and does not require the activation of the aryl ring. Moreover, the catalyst can be recovered and reused for five runs with identical results 50. The hydroarylation is highly efficient with trisubstituted double bonds involving the formation of five‐, six‐ or seven‐membered rings.…”

“…The hydroarylation is highly efficient with trisubstituted double bonds involving the formation of five‐, six‐ or seven‐membered rings. Terminal disubstituted olefins cyclised with CC bond formation when no ester functions are present; in the case of 14 , for example, the competition between the formation of the γ‐lactone 16 is favoured over the formation of the fused carbocycle 15 (Scheme ) 50. The olfactory evaluation of several of these compounds indicates various different notes, from fruity to flowery including also tobacco or amber notes (Figure 7).…”