A synthesis of geminally functionalized heterocyclic aminocarboxylic acids by cycloaddition of ethyl N-acetyl-α,β-dehydroalaninate with 1,3-dipoles

Horikawa, Hiroshi; Noji, Takashi; Iwasaki, Tameo; Inoue, Ichizo

doi:10.1016/s0040-4039(00)81880-8

Cited by 27 publications

(12 citation statements)

References 7 publications

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“…9 In order to rationalise the origin of regioselectivity, semiempirical (AM1) calculations were performed on ylidene piperazinediones 1a -1d and mesitonitrile oxide. From these calculations the electron densities at the a and b-carbon positions of the dipolarophile, as expressed by the orbital coefficients of these atoms, were determined.…”

Section: Regioselectivity Of 13-dpc Reactionsmentioning

confidence: 99%

Directed 1,3-dipolar cycloadditions of ylidene piperazine-2,5-diones

et al. 2003

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Section: Regioselectivity Of 13-dpc Reactionsmentioning

confidence: 99%

Directed 1,3-dipolar cycloadditions of ylidene piperazine-2,5-diones

et al. 2003

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“…Similarly low yields have been reported by Horikawa et al and El Abdioui et al in related systems. 9 In our experience, even lower yields were observed in the presence of metal catalysts such as Rh 2 (OAc) 4 which are known to mediate carbenoid additions to olefins. Carbene recombination to form diethyl fumarate was the likely cause of the low yields and we identified this as a by-product of the reactions.…”

Section: Synthesis Of Cyclopropane Amino Acidsmentioning

confidence: 77%

“…We next considered the use of vinyl diazomethane 8 as a masked carbonyl species -oxidation of the vinyl unit at a later stage could expose the required carbonyl. Substituted diazomethanes can undergo 3 ϩ 2 dipolar cycloaddition reactions with olefins to form dihydropyrazoles 9 which extrude N 2 to form cyclopropanes. Vinyl diazomethane 8 can be prepared by the base catalysed rearrangement of N-nitroso compounds, but a better method is in situ generation from its corresponding tosyl hydrazone salt, as described and used by Aggarwal et al 10 Accordingly, acrolein 9 was treated with tosyl hydrazine in dioxane to afford the tosyl hydrazone 10 in good yield (Scheme 2).…”

Section: Synthesis Of Cyclopropane Amino Acidsmentioning

confidence: 99%

Efficient synthesis of protected cyclopropyl β-aspartylphosphates

et al. 2004

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The in situ reaction of protected dehydroamino acids with derivatives of vinyldiazomethane leads to good to excellent yields of vinyl cyclopropanes via 3 + 2 dipolar cycloaddition followed by N(2) extrusion. Chromatographic separation of the cyclopropane diastereomeric products, followed by characterisation by (1)H NMR and X-ray crystallography allowed the cis and trans diastereomers to be easily identified. Oxidative cleavage of the vinyl moiety then led directly to protected cyclopropane aspartic acid derivatives in three steps from commercially available materials. These compounds were converted to protected methylenephosphonate, difluoromethylenephosphonate and phosphoramidate analogues of [small beta]-aspartyl phosphate.

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“…Methyl ester 80 was formed from the reaction of methyl 2‐(methylthio)acrylate 77 with diazomethane. In the same way, ethyl 2‐(acetamido)acrylate 78 underwent regiospecific 1,3‐dipolar cycloaddition with diazomethane to give pyrazoline‐3‐carboxylate 81 in 95% yield (Scheme ) .…”

Section: Synthetic Methodsmentioning

confidence: 99%