Rhenium-Catalyzed Insertion of Terminal Acetylenes into a C−H Bond of Active Methylene Compounds

Kuninobu, Yoichiro; Kawata, and Atsushi; Takai, Kazuhiko

doi:10.1021/ol0515208

Cited by 102 publications

(61 citation statements)

References 25 publications

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“…[4] These reported catalytic systems are, in general, only efficient for the intramolecular and/or intermolecular addition of the b-keto esters to terminal alkynes. In contrast, the intermolecular addition of the 1,3-diketones to terminal alkynes requires harsh reaction conditions such as high catalyst loading, high temperature, long reaction time, and large excess of alkynes; moreover, in some cases, addition of n-BuLi is required to suppress the by-product formation so as to obtain the desired products in good yields.…”

Section: Introductionmentioning

confidence: 99%

Hydro(trispyrazolyl)borato‐Ruthenium(II) Diphosphinoamino Complex‐Catalyzed Addition of β‐Diketones to 1‐Alkynes and Anti‐Markovnikov Addition of Secondary Amines to Aromatic 1‐Alkynes

Cheung

Pun

et al. 2011

Adv Synth Catal

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Section: Introductionmentioning

confidence: 99%

Hydro(trispyrazolyl)borato‐Ruthenium(II) Diphosphinoamino Complex‐Catalyzed Addition of β‐Diketones to 1‐Alkynes and Anti‐Markovnikov Addition of Secondary Amines to Aromatic 1‐Alkynes

Cheung

Pun

et al. 2011

Adv Synth Catal

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“…[12] The [ReBr(CO) 5 ]-catalyzed reaction of the silyl ether derivative 15 was also successful. Furthermore, the Re catalyst system was effective for a variety of 6-membered azacycles, such as the 4-phenylpiperidine and morpholine derivatives 17 and 19, which were converted into the corresponding tricyclic indoles fused with a 7-membered ring in good yield (Table 4, entries 3 and 4).…”

mentioning

confidence: 99%

Synthesis of N‐Fused Tricyclic Indoles by a Tandem [1,2] Stevens‐Type Rearrangement/1,2‐Alkyl Migration of Metal‐Containing Ammonium Ylides

et al. 2008

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We reported previously that novel metal-containing carbonyl or azomethine ylides could be generated by the nucleophilic attack of a carbonyl oxygen atom or imino nitrogen atom onto alkynes activated by electrophilic transition-metal complexes. The resulting species, which behave as both ylides ([3+2] cycloaddition) and carbene complexes (e.g. C À H insertion, 1,2-H or 1,2-alkyl shift), can be used as intermediates for the efficient preparation of synthetically useful, polycyclic compounds.[1] To expand the concept of metal-containing ylides, we have examined the generation and reaction of a newly designed metal-containing ammonium ylide, [2] which would enable concise access to a variety of polycyclic indoles with an N-fused ring. A recent report by Zhang and co-workers on a Pt-catalyzed reaction of N-(2-alkynylphenyl)lactams [3] prompted us to report our own approach, in which the main difference is the use of N-(2-alkynylphenyl)amines instead of lactams as the nucleophilic component. This transformation requires the use of [W(CO) 6 ] or [ReBr(CO) 5 ] as the alkynophilic reagent.The underlying strategy for the catalytic process described herein is depicted in Scheme 1: Upon the treatment of o-alkynylphenyl pyrrolidine or piperidine derivatives 1 with an appropriate electrophilic transition-metal complex, metalcontaining ammonium ylides A would be generated by the nucleophilic attack of the nitrogen atom onto the electrophilically activated alkyne moiety. Ylides A would then undergo ring expansion through a [1,2] Stevens-type rearrangement [4] to give carbene complexes B, which would undergo subsequent 1,2-alkyl migration to form N-fused tricyclic indole derivatives 2 with regeneration of the catalyst.After extensive screening of transition-metal catalysts and reaction conditions with N-(2-(prop-1-ynyl)phenyl)pyrrolidine (1 a) as the substrate, we found that the photoirradiation of a solution of 1 a and [W(CO) 6 ] (10 mol %) in toluene in the presence of 5-molecular sieves at room temperature gave the desired tricyclic indole derivative 2 a in 65 % yield (Table 1, entry 1). Photoirradiation was crucial for the efficient generation of the unsaturated tungsten species; the reaction under thermal conditions (toluene, 80 8C) resulted in lower conversion even with 300 mol % of [W(CO) 6 ] ( Table 1, entry 2).Careful analysis of the product by 2D NMR spectroscopy confirmed the formation of a tricyclic indole system with an N-fused six-membered ring and a methyl substituent at the 3 position of the indole nucleus. This result supported the validity of our original strategy. [5,6] Other metal catalysts, such as PtCl 2 , PtCl 4 , [AuPPh 3 ]SbF 6 , AuBr 3 , and [{IrCl(cod)} 2 ], were found to be inactive for this transformation under thermal or photoirradiation conditions, probably as a result of deactivation of the catalyst through strong coordination of the amine Scheme 1. Strategy for the generation of a metal-containing ammonium ylide and its tandem [1,2] Stevens-type rearrangement/1,2-alkyl migration. Table 1: Examin...

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“…For example, treatment of a mixture of 1,3-diketone 3 and phenylacetylene (4) with [ReBr(CO) 3 (thf)] 2 in toluene at 50 °C for 24 h gave the alkenylated adduct 5 in 94 % yield (eq. 7) [6]. In this reaction, a regioisomer generated by C-C bond formation at the terminal carbon atom of the alkyne was not observed.…”

Section: Insertion Of Alkynes Into a C-h Bond Of 13-dicarbonyl Compomentioning

confidence: 74%

Rhenium- and manganese-catalyzed carbon–carbon bond formation using 1,3-dicarbonyl compounds and alkynes

Kuninobu

Kawata

et al. 2010

Pure and Applied Chemistry

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A rhenium complex, [ReBr(CO) 3 (thf)] 2 , catalyzed insertion of terminal alkynes into a C-H bond of active methylene sites of 1,3-dicarbonyl compounds. When a catalytic amount of isocyanide or molecular sieves was added to the reaction mixture, the reaction course changed markedly, and insertion of alkynes into a C-C single bond between αand β-positions of cyclic and acyclic β-keto esters occurred. The formed acyclic δ-keto esters could be converted to 2-pyranones, which were applied to the synthesis of multisubstituted aromatic compounds via the Diels-Alder reaction and successive elimination of carbon dioxide. In the case of the rhenium-catalyzed reactions between terminal alkynes and β-keto esters without substituent at the α-position, tetrasubstituted benzenes were produced regioselectively by two-to-one reaction of the components. The yields of tetrasubstituted benzenes were improved by using a manganese catalyst.Scheme 5 Proposed mechanism for the synthesis of tetrasubstituted benzenes. Scheme 6Proposed mechanism for the synthesis of 2-pyranones.

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Rhenium-Catalyzed Insertion of Terminal Acetylenes into a C−H Bond of Active Methylene Compounds

Cited by 102 publications

References 25 publications

Hydro(trispyrazolyl)borato‐Ruthenium(II) Diphosphinoamino Complex‐Catalyzed Addition of β‐Diketones to 1‐Alkynes and Anti‐Markovnikov Addition of Secondary Amines to Aromatic 1‐Alkynes

Hydro(trispyrazolyl)borato‐Ruthenium(II) Diphosphinoamino Complex‐Catalyzed Addition of β‐Diketones to 1‐Alkynes and Anti‐Markovnikov Addition of Secondary Amines to Aromatic 1‐Alkynes

Synthesis of N‐Fused Tricyclic Indoles by a Tandem [1,2] Stevens‐Type Rearrangement/1,2‐Alkyl Migration of Metal‐Containing Ammonium Ylides

Rhenium- and manganese-catalyzed carbon–carbon bond formation using 1,3-dicarbonyl compounds and alkynes

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