Selective Synthesis of Eight-Membered Cyclic Ureas by the [6 + 2] Cycloaddition Reaction of 2-Vinylazetidines and Electron-Deficient Isocyanates

Koya, Shunsuke; Yamanoi, Kenichi; Yamasaki, Ryu; Azumaya, Isao; Masu, Hyuma; Saito, Shinichi

doi:10.1021/ol902299p

Cited by 36 publications

(16 citation statements)

References 27 publications

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“…Reaction of 2-vinylazetidine 244 with electron-deficient isocyanates was reported by Saito and coworkers in 2009 [122]. This reaction goes through a zwitterionic intermediate 245, which can either evolve to an eight-membered cyclic urea 246 or imidate 247 through an S N 2 0 reaction or to the formation of the six-membered ring 248.…”

Section: Expansions Into Six-membered Imidate and Ureamentioning

confidence: 95%

Ring Expansions of Nonactivated Aziridines and Azetidines

Couty

David

2015

Topics in Heterocyclic Chemistry

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Ring expansions promoted by ring strain in aziridines and azetidines are reviewed in this chapter, putting emphasis on recent applications from the last decade. This vast subject cannot be surveyed here exhaustively, and the reader will be guided to relevant precedent reviews or key reports. Rather, special attention will be put on selected examples and their mechanistic details, aiming to demonstrate that high selectivity can be reached in these reactions. In this issue, this fastgrowing topic has been divided into two distinct chapters, this one dealing with "nonactivated" aziridines and azetidines. Therefore, the reader will only find here examples involving NH-or N-alkylaziridines and N-azetidines as substrates for ring expansions, while N-acyl, N-carbamoyl, or N-tosyl compounds, defined as "activated" substrates, will be presented in the next chapter. This distinction can appear quite arbitrary at first sight but is amply justified by the great difference in reactivity of these distinct substrates. The first part focuses on the ring expansions of nonactivated aziridines into up to seven-membered rings and is further divided into expansions involving the incorporation of one (or more) heteroatoms, followed by ring expansions involving only incorporation of carbon atoms. The same model is then followed for azetidines.

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Section: Expansions Into Six-membered Imidate and Ureamentioning

confidence: 95%

Ring Expansions of Nonactivated Aziridines and Azetidines

Couty

David

2015

Topics in Heterocyclic Chemistry

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“…A new and simple synthesis for azocine derivatives 108 by [6+2] cycloaddition reaction was suggested by Saito and co-workers. 44 Electron-deficient allenes 107 reacted with 2-vinylazetidine 106 giving azocines 108 in moderated yields (Scheme 33 ).…”

Section: Cycloadditionmentioning

confidence: 99%

Recent Advances in the Synthesis of Hydrogenated Azocine-Containing Molecules

Listratova

Voskressensky

2017

Synthesis

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“…In continuation of our exploration of the synthetic utilities of C–N bond cleavage, , we designed a new type of direct substitution reaction of 1-ferrocenylalkylamines taking advantage of activation of allenones by the amino groups. , As depicted in Scheme , nucleophilic addition of 1-ferrocenylalkylamine 1 to allenone 2 would generate ammonium salt I-2 , which would undergo 1,3-rearrangement, involving sequential C–N bond cleavage and C–C bond formation, followed by hydrolysis to afford 2-(1-ferrocenylalkyl)-1,3-diketone 3 . In this process, electrophilic allenone 2 would be activated by the amino group to yield enamine I -4 as a carbon nucleophile.…”

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confidence: 99%

Activation and Substitution of 1-Ferrocenylalkylamines with Allenones: Application to Three-Component Synthesis of 4-(1-Ferrocenylalkyl)pyrazoles

2017

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A one-pot, two-step three-component synthesis of 4-(1-ferrocenylalkyl)pyrazoles has been developed involving activation and substitution of 1-ferrocenylalkylamines with allenones under mild conditions. A range of 1-ferrocenylalkylamines reacted with allenones in the presence of dipicolinic acid at room temperature without extrusion of air and moisture, and the resulting crude products were treated with hydrazine to afford structurally diverse 4-(1-ferrocenylalkyl)pyrazoles in moderate to good yields. Moreover, the three-component reaction was successfully extended to an enantioenriched α-ferrocenylbenzylamine with complete retention of configuration.

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Selective Synthesis of Eight-Membered Cyclic Ureas by the [6 + 2] Cycloaddition Reaction of 2-Vinylazetidines and Electron-Deficient Isocyanates

Cited by 36 publications

References 27 publications

Ring Expansions of Nonactivated Aziridines and Azetidines

Ring Expansions of Nonactivated Aziridines and Azetidines

Recent Advances in the Synthesis of Hydrogenated Azocine-Containing Molecules

Activation and Substitution of 1-Ferrocenylalkylamines with Allenones: Application to Three-Component Synthesis of 4-(1-Ferrocenylalkyl)pyrazoles

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Selective Synthesis of Eight-Membered Cyclic Ureas by the [6 + 2] Cycloaddition Reaction of 2-Vinylazetidines and Electron-Deficient Isocyanates

Cited by 36 publications

References 27 publications

Ring Expansions of Nonactivated Aziridines and Azetidines

Ring Expansions of Nonactivated Aziridines and Azetidines

Recent Advances in the Synthesis of Hydrogenated Azocine-Containing­ Molecules

Activation and Substitution of 1-Ferrocenylalkylamines with Allenones: Application to Three-Component Synthesis of 4-(1-Ferrocenylalkyl)pyrazoles

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Resources

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Recent Advances in the Synthesis of Hydrogenated Azocine-Containing Molecules