Nickel-catalyzed [3+2+2] cycloaddition of ethyl cyclopropylideneacetate and diynes. Synthesis of 7,6- and 7,5-fused bicyclic compounds

Maeda, Katsutoshi; Saito, Shinichi

doi:10.1016/j.tetlet.2007.03.051

Cited by 54 publications

(15 citation statements)

References 25 publications

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“…Subsequently, they developed the cycloaddition of two different alkynes with the cyclopropylideneacetate, although the slow addition of substrates and the large excess of one alkyne component were required 2g. They also developed the partial intramolecular [3+2+2] cycloaddition of a 1,6‐diyne with cyclopropylideneacetate 2e. A proposed mechanism of the nickel(0)‐catalyzed [3+2+2] cycloaddition reactions is shown in Scheme 2a,c–h.…”

Section: Methodsmentioning

confidence: 99%

Rhodium‐Catalyzed [3+2+2] and [2+2+2] Cycloadditions of Two Alkynes with Cyclopropylideneacetamides

et al. 2015

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It has been established that ac ationic rhodium(I)/ H 8 -binap complex catalyzesthe [3+ +2+ +2] cycloaddition of 1,6-diynes with cyclopropylideneacetamides to produce cycloheptadiene derivatives through cleavage of cyclopropane rings. In contrast, acationic rhodium(I)/(S)-binap complex catalyzes the enantioselective [2+ +2+ +2] cycloaddition of terminal alkynes,a cetylenedicarboxylates,a nd cyclopropylideneacetamides to produce spiro-cyclohexadiene derivatives which retain the cyclopropane rings.Transition-metal-catalyzed [3+ +2+ +2] cycloaddition reactions involving cyclopropylidene compounds are valuable methods for the construction of seven-membered rings.[1] Previously, ac yclopropylideneacetate as ac ycloaddition partner and anickel(0)/phosphine complex as acatalyst were used. [2,3] For example,S aito and co-workers reported the nickel(0)/phosphine-complex-catalyzed intermolecular [3+ +2+ +2] cycloaddition of two identical alkynes with the cyclopropylideneacetate.[2h] Subsequently,they developed the cycloaddition of two different alkynes with the cyclopropylideneacetate,a lthough the slow addition of substrates and the large excess of one alkyne component were required.[2g] They also developed the partial intramolecular [3+ +2+ +2] cycloaddition of a1 ,6-diyne with cyclopropylideneacetate.[2e] Ap roposed mechanism of the nickel(0)-catalyzed [3+ +2+ +2] cycloaddition reactions is shown in Scheme 1. [2a,c-h, 4] Tw oalkynes and cyclopropylideneacetate react with the nickel(0) complex to generate the nickelacycloheptadiene intermediate A.Ab-carbon atom elimination affords the nickelacyclooctadiene intermediate B and subsequent reductive elimination furnishes the cycloheptadiene derivative C.A lthough direct reductive elimination from A would furnish the spiro-cyclohexadiene derivative D,s uch reactions are limited to the case using sterically demanding phosphine ligands and proceeded in low yields. [2f, 5] Importantly,both cycloheptane [6] and spiro-cyclohexane [7] skeletons are frequently found in biologically active natural products.T herefore,t heir selective syntheses are important targets for organic synthesis.H erein, we have applied ac ationic rhodium(I)/biaryl bis(phosphine) catalyst, which is known to be ah ighly active catalyst for the [2+ +2+ +2] cycloaddition, [8,9] to the cycloaddition reactions involving cyclopropylidene compounds. [10] Our research group reported that acrylamide derivatives are highly reactive substrates in cationic rhodium(I)-complexcatalyzed [2+ +2+ +2] cycloaddition reactions.[11] Therefore,w e first examined the reaction of the 1,6-diyne 1a and N-methyl-N-phenylcyclopropylidene-acetamide (2a)inthe presence of cationic rhodium(I)/bisphosphine complexes,a ss hown in Table 1. We were pleased to find that the [3+ +2+ +2] cycloaddition of 1awith 2aproceeded using acationic rhodium(I)/ segphos catalyst (20 mol %) to give the [3+ +2+ +2] cycloaddition product 3aa in moderate yield along with the [2+ +2+ +2] cycloaddition product 4aa (entry 1). Screening of bis(phosphine...

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Section: Methodsmentioning

confidence: 99%

Rhodium‐Catalyzed [3+2+2] and [2+2+2] Cycloadditions of Two Alkynes with Cyclopropylideneacetamides

et al. 2015

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“…Later on, a three‐component co‐cyclization of ethyl cyclopropylideneacetate 27 , conjugated enynes 33 , and (trimethylsilyl)acetylene 34 was established in a highly selective manner to afford vinylcycloheptadienes 35 in good yield (Scheme 9, middle) [15c] . Interestingly, when the two alkyne moieties are tethered, the corresponding (1,n)‐diynes 36 [ n =1 or 2] could undergo the [3+2+2] cycloadditions under the same reaction conditions to give 7,5‐ or 7,6‐fused bicyclic compounds 37 with moderate yield, albeit with unsatisfactory E / Z selectivity of exocyclic double bond (Scheme 9, bottom) [15d] …”

Section: Transition‐metal‐catalyzed [3+2+2] Cycloaddition Reactionsmentioning

confidence: 99%

Transition‐Metal‐Catalyzed Cycloaddition Reactions to Access Seven‐Membered Rings

Trost

Zuo

Schultz

2020

Chemistry A European J

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The efficient and selective synthesis of functionalized seven‐membered rings remains an important pursuit within synthetic organic chemistry, as this motif appears in numerous drug‐like molecules and natural products. Use of cycloaddition reactions remains an attractive approach for their construction within the perspective of atom and step economy. Additionally, the ability to combine multiple components in a single reaction has the potential to allow for efficient combinatorial strategies of diversity‐oriented synthesis. The inherent entropic penalty associated with achieving these transformations has impressively been overcome with development of catalysis, whereby the reaction components can be pre‐organized through activation by transition‐metal‐catalysis. The fine‐tuning of metal/ligand combinations as well as reaction conditions allows for achieving chemo‐, regio‐, diastereo‐ and enantioselectivity in these transformations. Herein, we discuss recent advances in transition‐metal‐catalyzed construction of seven‐membered rings via combination of 2–4 components mediated by a variety of metals. An emphasis is placed on the mechanistic aspects of these transformations to both illustrate the state of the science and to highlight the unique application of novel processes of transition‐metals in these transformations.

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“…15 In their following reports, a variety of internal and terminal alkynes bearing different electron properties were successfully coupled under similar reaction conditions. 16 The replacement of alkyne moieties with tethered diynes 17 or dienes 18 were later realized, affording moderate to good yields and high regioselectivity (Scheme 8b). …”

Section: Three-membered Ringsmentioning

confidence: 99%

“Cut and Sew” Transformations via Transition-Metal-Catalyzed Carbon–Carbon Bond Activation

et al. 2017

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The transition metal-catalyzed “cut and sew” transformation has recently emerged as a useful strategy for preparing complex molecular structures. After oxidative addition of a transition metal into a carbon–carbon bond, the resulting two carbon termini can be both functionalized in one step via the following migratory insertion and reductive elimination with unsaturated units, such as alkenes, alkynes, allenes, CO and polar multiple bonds. Three- or four-membered rings are often employed as reaction partners due to their high ring strains. The participation of non-strained structures generally relies on cleavage of a polar carbon–CN bond or assistance of a directing group.

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Nickel-catalyzed [3+2+2] cycloaddition of ethyl cyclopropylideneacetate and diynes. Synthesis of 7,6- and 7,5-fused bicyclic compounds

Cited by 54 publications

References 25 publications

Rhodium‐Catalyzed [3+2+2] and [2+2+2] Cycloadditions of Two Alkynes with Cyclopropylideneacetamides

Rhodium‐Catalyzed [3+2+2] and [2+2+2] Cycloadditions of Two Alkynes with Cyclopropylideneacetamides

Transition‐Metal‐Catalyzed Cycloaddition Reactions to Access Seven‐Membered Rings

“Cut and Sew” Transformations via Transition-Metal-Catalyzed Carbon–Carbon Bond Activation

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