Cycloadditions of 1-aza-2-azoniaallene ions to alkenes

Wirschun, W.; Al‐Soud, Yaseen A.; Nusser, Konstanze A.; Orama, Olli; Maier, Gerd-Michael; Jochims, Johannes C.

doi:10.1039/b006525k

Cited by 25 publications

(28 citation statements)

References 43 publications

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“…Synthesis of 4,5-dihydro-3H-pyrazolium salts from ethylene. 112 In the presence of cesium carbonate, aldoxime-derived p-tosylhydrazones 67 (R 1 =H) reacted with calcium carbide-derived acetylene, giving NH-pyrazoles 68 (Scheme 42). 8d The application of ketone p-tosylhydrazones 67 (R 1 ≠H) led to NH-pyrazoles 69 (Scheme 42), with a small admixture of regioisomeric product, due to the unselective migration of the substituents during cycle formation.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Acetylene and Ethylene: Universal C2 Molecular Units in Cycloaddition Reactions

et al. 2021

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Section: Accepted Manuscriptmentioning

confidence: 99%

Acetylene and Ethylene: Universal C2 Molecular Units in Cycloaddition Reactions

et al. 2021

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“…4 Once formed, these cationic heteroallenes, which are 1,3-monopols, can react in concerted (3+2) cycloadditions with alkenes to give bicyclic diazenium salt products (Scheme 1, 1  3). [5][6][7] In addition, we have shown that these species, which can be thought of as imino-nitrenium cations, can react in C-H insertion reactions to give pyrazolines through a bonding stepwise but energy concerted amination process (Scheme 1, 4  6). 8,9 Scheme 1.…”

Section: Introductionmentioning

confidence: 99%

Intramolecular (4+2) cycloaddition of aryl-1-aza-2-azoniaallene salts: a practical approach to highly sterically-congested polycyclic protonated azomethine imines

Dhakal

Brewer

2016

Tetrahedron

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We report an improved two-step reaction sequence that gives tricyclic protonated azomethine imine products containing a 1,2,3,4-tetrahydrocinnoline scaffold in high yield. This sequence involves the oxidation of aryl hydrazones with TFAA-activated DMSO to give the corresponding α-trifluoroacetoxyazo products, which react readily with TMSOTf to give 1-aza-2-azoniaallene salt intermediates that undergo intramolecular (4+2) cycloadditions with pendent alkenes. This reaction sequence is more general, more practical and more environmentally friendly than our initially reported method. The cycloaddition provides exceptionally sterically-hindered products in high yield.

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“…S N MeOOC S N N Me Me N SCl COOMe N N Me Me SCl + ClO 4 _ 4 + ClO 4 _ 5 3 2 MeNO 2 -LiClO 4 1 -LiClIn the 1 H NMR spectra of compounds 4,5, the signals from the protons of the CHS and CHN + moieties appear as doublets with spin-spin coupling constant 7.9-8.0 Hz, which suggests an exo-cis configuration for these products [3,4].The 1 H and 13 C NMR spectra were taken on a Bruker DRX-500 (500 MHz and 125 MHz respectively) in DMSO-d 6 .Sulfenylation of Diene 1 (General Procedure). A solution of LiClO 4 (1.06 g, 10 mmol) in nitromethane (30 ml) and a solution of sulfenyl chloride 2 or 3 (10 mmol) in nitromethane (10 ml) were added to a solution of compound 1 (0.92 g, 10 mmol) in nitromethane (20 ml) at 20°C.…”

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confidence: 95%

“…In the 1 H NMR spectra of compounds 4,5, the signals from the protons of the CHS and CHN + moieties appear as doublets with spin-spin coupling constant 7.9-8.0 Hz, which suggests an exo-cis configuration for these products [3,4].…”

mentioning

confidence: 97%

Annelation of the Norbornene Skeleton in Reactions of Hetarene Sulfenyl Chlorides with Norbornadiene

Борисов¹,

Османов²,

Nikonova³

et al. 2005

Chem Heterocycl Compd

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Reaction of norbornadiene (1) with arenesulfenyl chlorides occurs nonselectively and leads to a mixture of isomeric β-chlorosulfides and rearrangement products [1,2].We have established that the only direction for the reactions of diene 1 with 3-methoxycarbonyl-2-pyridinesulfenyl chloride (2) and 4,6-dimethyl-2-pyrimidinesulfenyl chloride (3) in nitromethane in the presence of lithium perchlorate at 20°C is stereospecific cycloaddition of the sulfenylating reagent at the multiple bond, with closure of the ring by the nitrogen atom of the thiohetaryl moiety and formation of condensed systems 4, 5 in 87% and 75% yields respectively. S N MeOOC S N N Me Me N SCl COOMe N N Me Me SCl + ClO 4 _ 4 + ClO 4 _ 5 3 2 MeNO 2 -LiClO 4 1 -LiClIn the 1 H NMR spectra of compounds 4,5, the signals from the protons of the CHS and CHN + moieties appear as doublets with spin-spin coupling constant 7.9-8.0 Hz, which suggests an exo-cis configuration for these products [3,4].The 1 H and 13 C NMR spectra were taken on a Bruker DRX-500 (500 MHz and 125 MHz respectively) in DMSO-d 6 .Sulfenylation of Diene 1 (General Procedure). A solution of LiClO 4 (1.06 g, 10 mmol) in nitromethane (30 ml) and a solution of sulfenyl chloride 2 or 3 (10 mmol) in nitromethane (10 ml) were added to a solution of compound 1 (0.92 g, 10 mmol) in nitromethane (20 ml) at 20°C. After 10 min, the LiCl __________________________________________________________________________________________

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Cycloadditions of 1-aza-2-azoniaallene ions to alkenes

Cited by 25 publications

References 43 publications

Acetylene and Ethylene: Universal C2 Molecular Units in Cycloaddition Reactions

Acetylene and Ethylene: Universal C2 Molecular Units in Cycloaddition Reactions

Intramolecular (4+2) cycloaddition of aryl-1-aza-2-azoniaallene salts: a practical approach to highly sterically-congested polycyclic protonated azomethine imines

Annelation of the Norbornene Skeleton in Reactions of Hetarene Sulfenyl Chlorides with Norbornadiene

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