Alkynylhalocarbenes: generation from 1,1-dihaloalk-2-ynes by base solvolysis and reaction with alkenes

Shavrin, K. N.; Krylova, I. V.; Shvedova, I. B.; Okonnishnikova, G. P.; Dolgy, Igor E.; Нефедов, О. М.

doi:10.1039/p29910001875

Cited by 33 publications

(18 citation statements)

References 19 publications

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“…The sol vent was evaporated in vacuo, the residue obtained was dissolved in the hexane-diethyl ether (2 : 1) mixture, passed through a short layer of neutral Al 2 O 3 , a viscous substance obtained after repeated concentration (312 mg, 63%) according to the NMR spectroscopic data contained ~90% of 2 [1 (4 methoxyphenyl) 2 methylprop 2 yl]hexahydropyrimidine (17). Found Reaction of chlorocyclopropane 12b with lithium derivative of 1,3 diaminopropane.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of 5-methylidenehexahydropyrrolo[l,2-a]imidazoles and 6-methylideneoctahydropyrrolo[l,2-a]pyrimidines by the reaction of 1-alkynyl-1-chlorocyclopropanes with lithium derivatives of 1,2- and 1,3-diaminoalkanes

2010

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A reaction of 1 alkynyl 1 chlorocyclopropanes with excess of lithium derivative of 1,2 di aminoethane leads to 5 methylidenehexahydropyrrolo[1,2 a]imidazoles in 35-72% yields, whereas analogous reaction with lithium derivative of 1,3 diaminopropane gives 6 methyl ideneoctahydropyrrolo[1,2 a]pyrimidine in up to 50% yield. A mechanism of these unusual multi step processes includes dehydrochlorination of 1 alkynyl 1 chlorocyclopropanes to form conjugated alkynylcyclopropenes capable of addition of monoalkylamide ions at the double bond, leading to the corresponding secondary cyclopropylamines; the latter under the reaction conditions isomerize to the linear imines, which further undergo a cascade cyclization with sequential involvement of the C=N and C≡C bonds.

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Section: Methodsmentioning

confidence: 99%

Synthesis of 5-methylidenehexahydropyrrolo[l,2-a]imidazoles and 6-methylideneoctahydropyrrolo[l,2-a]pyrimidines by the reaction of 1-alkynyl-1-chlorocyclopropanes with lithium derivatives of 1,2- and 1,3-diaminoalkanes

2010

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“…Whereas much work concerning propargylmetal compounds has been done, 14 little was known concerning propargyl carbenoids when starting this study. However, in the literature were reported the formation of a,adifluoropropargylzinc 37 and indium 38 carbenoids, a,adichloropropargyllithiums 39 and potassiums 40 and lithiated a-fluoropropargylphosphonates. 41 On the other hand, the simple propargylic lithiocarbenoids generated by the deprotonation of the corresponding propargyl halides were described to display low stability and to undergo coupling to form enediynes.…”

Section: Highly Diastereoselective Access To Non-aromatic Acetylenic Oxiranesmentioning

confidence: 99%

Highly Diastereoselective Syntheses of Propargylic Acid and Homopropargylic Systems

Ferreira¹,

Denichoux²,

Chemla³

et al. 2004

Synlett

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The results of our research dealing with the stereoselective synthesis of propargylic and homopropargylic systems are summarized. In a first part, the stereoselective formation of syn-or anti-disubstituted homopropargylic alcohols from acetylenic oxiranes through S N 2 or double S N 2¢ has been developed. Thus, the two diastereomers of a given homopropargylic alcohol are stereospecifically available. The great impact of Lewis acid activation on the regioselectivity of the ring-opening reactions of propargylic oxiranes is also detailed. In a second part, the preparation and uses of new acetylenic/allenic carbenoids are overviewed; their reactivity towards carbonyl compounds and imines is examined, leading to the highly stereoselective synthesis of acetylenic chlorohydrins, oxiranes and aziridines.

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“…α,α-Difluoropropargylzinc [3,4] (Scheme 1, X ϭ Y ϭ F, M ϭ ZnBr) and propargylindium [5,6] (Scheme 1, X ϭ Y ϭ F, M ϭ InBr) carbenoids have been described, as have α,α-dichloropropargyllithium [7] (Scheme 1, X ϭ Y ϭ R ϭ Cl, M ϭ Li), α,α-dichloropropargylpotassium [8] (Scheme 1, X ϭ Y ϭ Cl, M ϭ K), and lithiated α-fluoropropargylphosphonate [9] [Scheme 1, X ϭ F, Y ϭ PO(OEt) 2 , M ϭ Li]. Scheme 1 On the other hand, it has been shown that the simplest propargylic lithiocarbenoids [10Ϫ14] (Scheme 1, X ϭ H or alkyl, Y ϭ Cl or Br, M ϭ Li), prepared by deprotonation of propargyl halides, display low thermal stabilities and undergo coupling to form enediynes (Scheme 2).…”

Section: Introductionmentioning

confidence: 99%

Preparation of Propargylic Carbenoids and Reactions with Carbonyl Compounds − A Stereoselective Synthesis of Propargylic Halohydrins and Oxiranes

et al. 2001

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Alkynylhalocarbenes: generation from 1,1-dihaloalk-2-ynes by base solvolysis and reaction with alkenes

Cited by 33 publications

References 19 publications

Synthesis of 5-methylidenehexahydropyrrolo[l,2-a]imidazoles and 6-methylideneoctahydropyrrolo[l,2-a]pyrimidines by the reaction of 1-alkynyl-1-chlorocyclopropanes with lithium derivatives of 1,2- and 1,3-diaminoalkanes

Synthesis of 5-methylidenehexahydropyrrolo[l,2-a]imidazoles and 6-methylideneoctahydropyrrolo[l,2-a]pyrimidines by the reaction of 1-alkynyl-1-chlorocyclopropanes with lithium derivatives of 1,2- and 1,3-diaminoalkanes

Highly Diastereoselective Syntheses of Propargylic Acid and Homopropargylic Systems

Preparation of Propargylic Carbenoids and Reactions with Carbonyl Compounds − A Stereoselective Synthesis of Propargylic Halohydrins and Oxiranes

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