Uncovering Reaction Pathways of 1-Aminocyclohexenes with [(1-Alkynyl)carbene]tungsten Complexes Leading to Cyclopentadienes and Dihydropyrroles

Aumann, Rudolf; Kößmeier, Michael; Mück‐Lichtenfeld, Christian; Zippel, Frank

doi:10.1002/(sici)1099-0690(200001)2000:1<37::aid-ejoc37>3.0.co;2-p

Cited by 17 publications

(3 citation statements)

References 34 publications

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“…[15] It should be noted that the reaction proceeds selectively with the formation of one product at An example of the formation of an eight-membered carbocycle from a bicyclic compound is presented in the work of the group of Rudolf Aumann. [16] Reactions of the tungsten complex 40 with 1-aminocyclohexenes 41 a-c afford to 43 a-c with 52-74 % yield (Scheme 14). At the first step of this reaction, a bicyclic product 42 is formed, which is transformed into a monocyclic one.…”

Section: Four-membered Carbocyclesmentioning

confidence: 99%

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Cycloaddition Reactions of Enamines

et al. 2023

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This review includes information for around two last decades on cycloaddition reactions of enamines with various agents in order to build carbo‐ and heterocycles. In addition, the review presents organo‐catalytic reactions in which enamines are intermediate products generated in situ. This review covers the synthesis of four, five, six and eight‐membered carbocyclic compounds, as well as heterocycles as pyrroles, pyridines, etc.

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Section: Four-membered Carbocyclesmentioning

confidence: 99%

“…An example of the formation of an eight‐membered carbocycle from a bicyclic compound is presented in the work of the group of Rudolf Aumann [16] . Reactions of the tungsten complex 40 with 1‐aminocyclohexenes 41 a – c afford to 43 a – c with 52–74 % yield (Scheme 14).…”

Section: Carbocyclization Reactionsmentioning

confidence: 99%

Cycloaddition Reactions of Enamines

et al. 2023

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“…However, this was not the case, as the major reaction products in our first experiments with DEAD (diethyl azodicarboxylate) were the ring-fused cyclopentadienes E , bearing a diaza moiety at the C3a bridgehead position, which was derived from the spontaneous, regioselective C1–N8 bond cleavage . This serendipitous discovery led us to study mechanistically this process and extend the scope to a variety of substrates and azodicarboxylates in order to establish a protocol for the synthesis of such complex, polyfunctionalized cyclopentadiene structures bearing a N functionality (a masked amino group) at the bridgehead position that are otherwise very difficult to synthesize …”

Section: Introductionmentioning

confidence: 99%

Gold(I)-Catalyzed Cycloisomerization/Hetero-Diels–Alder Reaction/Ring Opening Cascade to Functionalized Cyclopentadienes

et al. 2022

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Six- and seven-membered ring-fused, functionalized cyclopentadienes can be obtained in moderate to excellent yields by a cascade process entailing the Au(I)-catalyzed propargyl Claisen rearrangement/Nazarov cyclization of propargyl vinyl ethers, the hetero-Diels–Alder reaction with dialkylazodicarboxylates, and the spontaneous conversion of cycloaddition products into cyclopentadienes by a highly regioselective cleavage of a C–N bond. Depending on the treatment of the crude reaction mixtures, two types of products can be obtained: cyclopentadienes with pendant hydrazine and aldehyde moieties that intramolecularly react to form hemiaminals are obtained in 43–52% overall yields when the crude reaction mixtures are left over K2CO3 in a DCM solution. Instead, by reducing in situ the aldehyde group just after addition of the heterodienophile, the regioselective C–N bond cleavage generates the corresponding cyclopentadienes bearing a hydrazine and an alcohol appendage in excellent yields (66–82%) over four steps, all in one pot. Two examples from the latter class of compounds were also converted into ring-fused, functionalized cyclopentadienes, bearing a protected amino group, by the selective N–N cleavage of the hydrazine moiety.

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