Cyclisations Catalysed by Bismuth(III) Triflate

Ondet, Pierrick; Lemière, Gilles; Duñach, Élisabet

doi:10.1002/ejoc.201600937

Cited by 60 publications

(34 citation statements)

References 111 publications

(100 reference statements)

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“…The recycling of catalyst has been an important requirement in decreasing environmental pollution and reducing the cost in the industrial process . There is some debate about the nature of active species such as a low‐concentration of triflic acid, which is formed in the hydrolysis of bismuth triflate . However, Lambert and coworkers reported that Bi(OTf) 3 in the presence of substrates indicate that Lewis acid/base interactions are necessary to liberate TfOH .…”

Section: Resultsmentioning

confidence: 99%

Greener Friedel‐Crafts Acylation Using Microwave‐Enhanced Reactivity of Bismuth Triflate in the Friedel‐Crafts Benzoylation of Aromatic Compounds with Benzoic Anhydride

et al. 2017

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An efficient and facile bismuth trifluoromethanesulfonate‐catalyzed benzoylation of aromatic compounds using benzoic anhydride under solvent‐free microwave irradiation has been developed. The microwave‐assisted Friedel‐Crafts benzoylation results in good yields within short reaction times. Bismuth triflate is easily recovered and reused for several times without significant loss of catalytic activity.

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Section: Resultsmentioning

confidence: 99%

Greener Friedel‐Crafts Acylation Using Microwave‐Enhanced Reactivity of Bismuth Triflate in the Friedel‐Crafts Benzoylation of Aromatic Compounds with Benzoic Anhydride

et al. 2017

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“…The reaction at 40°C (entry 9) gave 3a as a major product (47%). When we carried out the reaction at 25°C, 3a was obtained in good yield (55%) …”

Section: Methodsmentioning

confidence: 99%

One‐Pot Synthesis of 3‐(Benzo[e]indol‐2‐yl)‐2‐oxindoles from Isatin‐derived Propargylic Alcohols and N‐Acetyl‐2‐aminonaphthalenes

Roh

Seo

Ryu

et al. 2017

Bulletin Korean Chem Soc

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3-Aryloxindoles have been used as important synthetic intermediates of many biologically important 3,3-disubstituted oxindoles and indolines.1,2 Typically, 3-aryloxindoles have been prepared by the cyclization of α-aryl acetanilides, 2a-d palladium or nickel-catalyzed arylation of oxindoles, 2e-j arylation of 3-diazooxindoles with arenes or aryl boron reagents, 2k-p or arylation of isatins using aryl Grignard reagents and subsequent reduction. 2q-tThe reported aryl moieties of 3-aryloxindoles included phenyl, substituted phenyl, and heteroaryl groups including thiophene, 2k,m,q pyrrole, 2p or indole. 2o,q Recently, we reported an efficient one-pot synthesis of 3-naphtho[2,1-b] furanyl-2-oxindoles from isatin-derived propargylic alcohols and 2-naphthols. 3 The naphtho[2,1-b]furan ring was formed via Michael type 5-exo-dig cyclization of the corresponding allene intermediate.As a continuing study, we reasoned out that a replacement of 2-naphthol to N-acetyl-2-aminonaphthalene (2a) would afford 3-(benzo[e]indol-2-yl)-2-oxindole derivative 3a, as shown in Scheme 1. 2-Oxindoles bearing benzo [e] indole moiety at the 3-position have not been reported, to the best of our knowledge. 4 The reaction of 2a and the Boc carbonate of isatin-derived propargylic alcohol 1a in the presence of p-TsOH (10 mol %) in 1,2-dichloroethane (DCE) for 1 h afforded 3a in a reasonable yield (47%). Compound 3a might be formed via regioselective FriedelCrafts allenylation 5 of 2a to form an allene intermediate I and a following Michael type 5-exo-dig cyclization. The formation of spirooxindole II, which could be formed via 6-endo-dig cyclization of I, was not observed. The selective 5-exo-dig cyclization might be attributed to the presence of an electron-withdrawing carbonyl group of isatin moiety. The formation of a trace amount of N-deacetylated compound 4a (<5%) was observed (vide infra). The reaction of 2-aminonaphthalene and 1a in the presence of p-TsOH in refluxing DCE did not produce 4a. The protonation of 2-aminonaphthalene under the acidic condition would render the C-1 position of naphthalene ring less nucleophilic. 6 In order to increase the yield of 3a, the reaction of 1a and 2a was examined under the reaction conditions shown in Table 1. The reaction at low temperature (40 C, 4 h) afforded 3a in a slightly lower yield (43%, entry 2). The reaction proceeded even at 25 C (entry 3). However, the reaction was slow and 3a was obtained in low yield (35%) even after 10 h. The reaction in CH 3 CN was less effective (entry 4). The use of InCl 3 (entry 5) or Yb(OTf ) 3 (entry 6) showed a similar result to that of p-TsOH. The use of Cu(OTf ) 2 (entry 7) was less efficient. It is interesting to note that the use of Bi(OTf ) 3 in refluxing DCE (entry 8) afforded 4a as a major product (49%).7 The reaction at 40 C (entry 9) gave 3a as a major product (47%). When we carried out the reaction at 25 C, 3a was obtained in good yield (55%). 8,9 Encouraged by the successful results, we prepared various Boc carbonates 1a-1h 10 and aminonaphthalene de...

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“…[4] In this area, bismuth(III) triflate is known for its wide applicability to the activation of various chemical functions in cyclisation reactions. [5] Recently, we developed new cyclisation reactions involving functionalised enol ethers displaying a tertiary alcohol motif and an alkene [6] or an allene [7] function. Specifically designed enol ethers were shown to undergo tandem cyclisations under acidic conditions, leading to the formation of oxanorbornane spirocyclic diethers (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

“…In the course of our ongoing research on Lewis superacid‐catalysed reactions, our interest was focused on the development of new catalytic methodologies for the preparation of novel fragrance ingredients . In this area, bismuth(III) triflate is known for its wide applicability to the activation of various chemical functions in cyclisation reactions …”

Section: Introductionmentioning

confidence: 99%

Stereocontrolled Cascade Cyclisation of Campholenic Enol Ether Derivatives: En Route to Vetiver‐Scented Spiroxides

et al. 2018

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The Lewis superacid‐catalysed cascade cyclisation of enol ethers derived from campholenal resulted in an elegant reaction leading to new elaborated spirocyclic ethers. Under identical conditions, the reaction proceeded by two distinct mechanisms, depending on the relative configuration of the starting substrate. Hence, either a tandem cyclisation process gave access to tetracyclic spirodiethers, while another process involving a less common reaction sequence (cyclisation/1,4‐hydride shift) led to complex tricyclic spiroalcohols and/or spiroketones. Investigations on synthetic intermediates by enantioselective gas chromatography permitted to assess the high stereospecificity of the process. Collectively, these expedite syntheses gave access to unprecedented spiroxides which displayed, in some instances, strong vetiver‐like olfactory notes. While campholenic derivatives have long been used in the industrial production of fragrant sandalwood substitutes, these new derivatives provide potential synthetic alternatives to the esteemed natural ingredient vetiver.

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Cyclisations Catalysed by Bismuth(III) Triflate

Cited by 60 publications

References 111 publications

Greener Friedel‐Crafts Acylation Using Microwave‐Enhanced Reactivity of Bismuth Triflate in the Friedel‐Crafts Benzoylation of Aromatic Compounds with Benzoic Anhydride

Greener Friedel‐Crafts Acylation Using Microwave‐Enhanced Reactivity of Bismuth Triflate in the Friedel‐Crafts Benzoylation of Aromatic Compounds with Benzoic Anhydride

One‐Pot Synthesis of 3‐(Benzo[e]indol‐2‐yl)‐2‐oxindoles from Isatin‐derived Propargylic Alcohols and N‐Acetyl‐2‐aminonaphthalenes

Stereocontrolled Cascade Cyclisation of Campholenic Enol Ether Derivatives: En Route to Vetiver‐Scented Spiroxides

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