Obtention d'heterocycles azotes par addition intramoleculaire de radicaux amines neutres

Surzur, Jean‐Marie; Stella, Lucien; Tordo, Paul

doi:10.1016/s0040-4039(01)98426-6

Cited by 39 publications

(21 citation statements)

References 5 publications

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“…Solvents were distilled from LiAlH 4 (pentane, diethyl ether) or sodium benzophenone (THF). 1-Phenyl-6-bromo-1-hexyne, [21] 1-phenyl-5-bromo-1-pentyne, [22] 5-bromo-2-pentyne [23] and isopropyl-prop-2-enylamine [24] (20 d) were synthesized according to literature methods. The secondary amines were synthesized according to the procedure of Surzur et al [24] Na 2 Fe(CO) 4 ·1.5 dioxane (Collmans reagent) was purchased from Fluka or synthesized according to literature procedures.…”

Section: Methodsmentioning

confidence: 99%

Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)₄ Complexes with Dynamic Phosphinidene Behavior

Borst

Riet

Lemmens

et al. 2005

Chemistry A European J

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The synthesis of highly strained bicyclic phosphirane and phosphirene iron–tetracarbonyl complexes, that is, complexes with 2‐aza‐1‐phosphabicyclo[n.1.0]alkanes and ‐alkenes (n=3–5), is explored by using intramolecular cycloaddition of an in situ generated electrophilic phosphinidene complex, [R(iPr)NPFe(CO)4], to its CC‐ and CC‐containing R substituent. Saturated bicyclic complexes 7 a–c with n=4–2 are remarkably stable, as illustrated by the X‐ray crystal structure for 7 b (n=3), yet all readily undergo retroaddition to react with phenylacetylene. Shuttling of the phosphinidene iron complex between two equivalent CC groups is demonstrated for a 1‐butene‐substituted 2‐aza‐1‐phosphabicyclo[3.1.0]hexane by selective 1H NMR magnetization transfer from the phosphirane protons to the olefinic protons. Even the more strained unsaturated bicycles 17 a,b (n=4,3) are surprisingly stable as illustrated by the X‐ray crystal structure for 17 a (n=4), but the smaller phosphabicyclo[3.1.0]hex‐5‐ene (17 c, n=2) dimerizes to tricyclic 19 with a unique ten‐membered heterocyclic ring; an X‐ray crystal structure is reported. Like their saturated analogues also the bicyclic phosphirenes readily undergo retroaddition as shown by the reaction of their phosphinidene iron moiety with phenylacetylene.

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Section: Methodsmentioning

confidence: 99%

Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)₄ Complexes with Dynamic Phosphinidene Behavior

Borst

Riet

Lemmens

et al. 2005

Chemistry A European J

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“…Phosphoranyl radical cyclization (21,22) is unique in that the larger-membered rings are always formed exclusively. Amine radical cyclization (23)(24)(25)(26)) is in marked contrast to the failure 2Throughout this discussioll the radical center will be designated as position 1. of intermolecular amine radical addition which has been suggested to result from a high activation energy (27). In these cases (23)(24)(25)(26), however, the possibility has to be considered that aminium radical might be the reactive intermediate since hydrogen chloride is generated by side reactions of chloramines.…”

Section: Introductionmentioning

confidence: 99%

“…Amine radical cyclization (23)(24)(25)(26)) is in marked contrast to the failure 2Throughout this discussioll the radical center will be designated as position 1. of intermolecular amine radical addition which has been suggested to result from a high activation energy (27). In these cases (23)(24)(25)(26), however, the possibility has to be considered that aminium radical might be the reactive intermediate since hydrogen chloride is generated by side reactions of chloramines. An amine radical coordinated with titanous ion (or metal ion in general) has been proposed as the reactive intermediate in the titanous chloride catalysed chloramine decomposition (23,24).…”

Section: Introductionmentioning

confidence: 99%

“…In these cases (23)(24)(25)(26), however, the possibility has to be considered that aminium radical might be the reactive intermediate since hydrogen chloride is generated by side reactions of chloramines. An amine radical coordinated with titanous ion (or metal ion in general) has been proposed as the reactive intermediate in the titanous chloride catalysed chloramine decomposition (23,24). Such an intermediate behaves very similarly to an aminium radical.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of azacyclic compounds by an aminium radical route: orbital overlap requirements

Perry¹,

Chen²,

Menon³

et al. 1976

Can. J. Chem.

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Can. J. Chem. 54, 2385 (1976. Model compounds of A4v5-, A5.'j-, and a6.7-alkenylnitrosarnines were synthesized and photolyzed to generate the corresponding alkenylaminium radicals. The A5~6-alkenylan~inium radicals underwent efficient intramolecular addition leading to the exclusive formation of pyrrolidine derivatives, the yield of which was lower if the steric strain and hindrance were severe in the cyclization transition state. The A6s7-alkenylaminium radical cyclized inefficiently to piperidine derivatives and the A4~5-alkenylarninium radicals did not appear to cyclize; in both cases other pathways having lower activation energies, such as elimination and hydrogen abstraction, predominated. Evidence that the direction of cyclization is controlled by the degree of p-orbital overlap, but not by stability of the developing products, in the transition state is presented. The stereochernical factors associated with the overlap determined the yields of the cyclization products. This is in excellent agreement with the fact that the transition state of cyclization is reached at an early stage in the reaction coordinate. Metal ion catalyzed or radical initiated decomposition of some alkenyl chlorarnines were found either to cyclize to a mixture of pyrrolidine and piperidine derivatives or to undergo no cyclization. Chem. 54, 2385Chem. 54, (1976.On a synthetise et photolyse des cornposCs rnodkles de A4n5-, A5s6-et A6r7-alkenylnitrosarnines qui ont conduit aux radicaux alkknylarninium correspondants. Les radicaux A5:6-alkenylaminium subissent des rkactions d'addition intrarnoliculaires efficaces conduisant a la formation exclusive de derives de la pyrolidine; le rendement de ce compose est diminui si l'emp@chernent et la contrainte stCrique sont importants dans l'etat de transition rnenant a la cyclisation. Le radical A6r7-alkknylarniniurn se cyclise d'une fason inefficace pour conduire a des derives de la piperidine et les radicaux A4.5-alkknylarninium ne sernblent pas se cycliser; dans les deux cas d'autres chernins rkactionels ayant des energies d'activation plus basses, tels que les Climinations et les enlkvernents d'hydrogkne, prkdorninent. On prCsente des donnees indiquant que la direction de la cyclisation est contr6lk par le degrC de recouvrement des orbitales p dans 1'Ctat de transition; il ne semble pas que cette direction soit influenck par la stabilitk des produits qui se forrnent. Les facteurs stCrCochimiques associks avec le recouvrement dkterrninent les rendernents des produits de cyclisation. Ceci est en excellent accord avec le fait que, dans les coordonnees de la reaction, 1'Ctat de transition de la cyclisation est atteint t6t. On a trouvC que les dtkornpositions catalyskes par les ions mCtalliques ou initiies par les radicaux de quelques chloramines d'alkknyles conduisent soit une cyclisation fournissant un mClange de dCrives de la pyrolidine et de la pipkridine soit qu'ils ne conduisent pas des cyclisations.[Traduit par le journal]

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“…All these data, and especially the fact that 28 (S = OMe) could be isolated and characterized as the free amine 22 (Scheme 2), are strongly in favour of the process involving the electrophilic chlorination of the enol ether double bond. It is interesting to note that the ratios of cyclized products 20 (ketone) and 21 (enol ether) are inverted, in going from solvolysis of en01 ether N-chloramine 6 Similar cyclization processes will occur for 11 and 14.…”

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confidence: 95%

Synthesis of bridged azabicyclic ketones. Solvolysis of enol ether ethylene ketal N-cholramines in acidic medium

Furstoss¹,

Tadayoni²,

Esposito³

et al. 1976

Can. J. Chem.

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Obtention d'heterocycles azotes par addition intramoleculaire de radicaux amines neutres

Cited by 39 publications

References 5 publications

Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)₄ Complexes with Dynamic Phosphinidene Behavior

Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)₄ Complexes with Dynamic Phosphinidene Behavior

Synthesis of azacyclic compounds by an aminium radical route: orbital overlap requirements

Synthesis of bridged azabicyclic ketones. Solvolysis of enol ether ethylene ketal N-cholramines in acidic medium

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Obtention d'heterocycles azotes par addition intramoleculaire de radicaux amines neutres

Cited by 39 publications

References 5 publications

Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)4 Complexes with Dynamic Phosphinidene Behavior

Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)4 Complexes with Dynamic Phosphinidene Behavior

Synthesis of azacyclic compounds by an aminium radical route: orbital overlap requirements

Synthesis of bridged azabicyclic ketones. Solvolysis of enol ether ethylene ketal N-cholramines in acidic medium

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Product

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Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)₄ Complexes with Dynamic Phosphinidene Behavior

Strained, Stable 2‐Aza‐1‐Phosphabicyclo[n.1.0]alkane and ‐alkene Fe(CO)₄ Complexes with Dynamic Phosphinidene Behavior