Rhodium catalysed cyclopropenation of acetylenes

Petiniot, N.; ANCIAUX, A. J.; Noels, Alfred F.; Hubert, Aurélia; Teyssié, Ph.

doi:10.1016/s0040-4039(01)94511-3

Cited by 113 publications

(44 citation statements)

References 5 publications

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“…The synthesis of ethyl 2,3-diphenylcycloprop-2-ene-l-curboxylute (2) by the Cu-catalyzed decomposition of ethyl diazoacetate in presence of diphenylacetylene has been described [3 11. Ethyl 2,3-diethylcyclopropp-2-ene-1-carboxylate (3) and ethyl 2-butylcycloprop-2-ene-I-carboxylate (4a) were obtained by reaction of hex-3-yne and hex-1-yne, respectively with ethyl diazoacetate in presence of Rh,(OAc), [32]. The same procedure was used for 4b.…”

Section: Experimental Partmentioning

confidence: 99%

Rh(II)‐Catalyzed Isomerizations of Cyclopropenes Evidence for Rh(II)‐Complexed Vinylcarbene Intermediates

Müller

Pautex

Doyle

et al. 1990

Helvetica Chimica Acta

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The thermocatalytic rearrangements of cyclopropenes 1 4 have been investigated in the presence of Rh(I1) perfluorobutyrate. 1,2,3-Triphenylcyclopropene (la) undergoes rearrangement to diphenylindene 5a or, with alkoxycyclopropene derivatives, to ccJ-unsaturated ketone 6. Furan formation occurs with 2,3-diphenylcyclopropenecarboxylate 2, but the diethyl counterpart 3 rearranges to dienoate 8.2-Alkylcyclopropenecarboxylates 4 afforded (E)-methylidenecyclopentane derivatives9 as the only isolable product in yields of ca. 35 %. A mechanism involving regio-and stereospecific cyclopropene ring opening to a Rh-complexed vinylcarbene and insertion of the latter into the C-H bond to give 9 is proposed. An analogous mechanism should account for the rearrangement products of 1 to 3.

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Section: Experimental Partmentioning

confidence: 99%

Rh(II)‐Catalyzed Isomerizations of Cyclopropenes Evidence for Rh(II)‐Complexed Vinylcarbene Intermediates

Müller

Pautex

Doyle

et al. 1990

Helvetica Chimica Acta

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“…2 Following this general procedure, ethyl 2-(diethoxymethyl)cycloprop-2-ene-1-carboxylate (1) was prepared in 72% yield by reaction of propionaldehyde diethyl acetal (2) with ethyl diazoacetate (Scheme 2), using dirhodium(II) tetraacetate as catalyst. The cyclopropene 1 was purified by column chromatography and could be kept in the freezer under nitrogen for several days.…”

Section: Methodsmentioning

confidence: 99%

“…2 This reaction offers a direct entry to highly functionalized cyclopropenes, 3 a very attractive class of strained rings that can be transformed into a wide variety of compounds because of its high reactivity. 4 In the intramolecular version, the reaction of rhodium carbene complexes onto alkynes yields vinyl carbenoids that can be trapped in situ.…”

Section: Introductionmentioning

confidence: 99%

Diastereoselective addition of heteroatom nucleophiles to ethyl 2-(diethoxymethyl)-cycloprop-2-ene-1-carboxylate

Martinez‐Grau¹,

Blasco²,

Ferritto³

et al. 2005

Arkivoc

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“…Functionalized cyclopropenes are viable synthetic intermediates whose applications (37,38), which extend to a wide variety of carbocyclic and heterocyclic systems, have been largely ignored because of the relative inaccessibility of these strained compounds. However, recent advances in the synthesis of cyclopropenes, particularly from rhodium(II) carboxylate catalyzed decomposition of diazo esters in the presence of alkynes (39)(40)(41)(42), has made available an array of stable 3-cyclopropenecarboxylate esters. Previously, copper catalysts provided low to moderate yields of cyclopropenes in reactions of diazo esters with disubstituted acetylenes (43,44), but the higher temperatures required for these carbenoid reactions often led to thermal or catalytic ring opening and products derived from vinylcarbene intermediates (45)(46)(47)(48).…”

Section: Chiral Catalystsmentioning

confidence: 99%

Chiral Rhodium(II) Carboxamides

Doyle

1993

ACS Symposium Series

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Dirhodium(II) tetrakis(carboxamides), constructed with chiral 2-pyrrolidone-5-carboxylate esters so that the two nitrogen donor atoms on each rhodium are in a cis arrangement, represent a new class of chiral catalysts with broad applicability to enantioselective metal carbene trans formations. Enantiomeric excesses greater than 90% have been achieved in intramolecular cyclopropanation reactions of allyl diazoacetates. In intermolecular cyclopropanation reactions with monosubstituted olefins, the cis-disubstituted cyclopropane is formed with a higher enantiomeric excess than the trans isomer, and for cyclopropenation of 1-alkynes extraordinary selectivity has been achieved. Carbon-hydro gen insertion reactions of diazoacetate esters that result in substituted γ -butyrolactones occur in high yield and with enantiomeric excess as high as 90% with the use of these catalysts. Their design affords stabiliza tion of the intermediate metal carbene and orientation of the carbene substituents for selectivity enhancement.A select number of transition metal compounds are effective as catalysts for carbenoid reactions of diazo compounds Their catalytic activity depends on coordination unsaturation at their metal center which allows them to react as electrophiles with diazo compounds. Electrophilic addition to diazo compounds, which is the rate limiting step, causes the loss of dinitrogen and production of a metal stabilized carbene. Transfer of the electrophilic carbene to an electron rich substrate (S:) in a subsequent fast step completes the catalytic cycle (Scheme I). Lewis bases (B:) such as nitriles compete with the diazo compound for the coordinatively unsaturated metal center and are effective inhibitors of catalytic activity. Although carbene complexes with catalytically active transition metal compounds have not been observed as yet, sufficient indirect evidence from reactivity and selectivity correlations with stable metal carbenes (4,5) exist to justify their involvement in catalytic transformations.Transition metal catalysts that are effective for carbenoid transformations include those of copper(I), palladium(II) or platinum(II), cobalt(II), and rhodium(II) (7-5, 6-8), but only copper and rhodium catalysts have been routinely employed.

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Rhodium catalysed cyclopropenation of acetylenes

Cited by 113 publications

References 5 publications

Rh(II)‐Catalyzed Isomerizations of Cyclopropenes Evidence for Rh(II)‐Complexed Vinylcarbene Intermediates

Rh(II)‐Catalyzed Isomerizations of Cyclopropenes Evidence for Rh(II)‐Complexed Vinylcarbene Intermediates

Diastereoselective addition of heteroatom nucleophiles to ethyl 2-(diethoxymethyl)-cycloprop-2-ene-1-carboxylate

Chiral Rhodium(II) Carboxamides

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