Über einige Reaktionen des Äthylen‐imins

Bestian, H.

doi:10.1002/jlac.19505660210

Cited by 171 publications

(28 citation statements)

References 10 publications

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“…The resulting major product, N-(2-chloroethyl)methacrylamide, gave the following NMR signals: b 5.60/5.30 (s, CH 2 =C-), 3.51 (m, NH-(CH 2 )-Cl), and 1.91 (s, C = C-CH 3 ). This product was identical in all respects to authentic material prepared from methacryloyl chloride and aziridine according to the method of Bestian et al 12 …”

Section: Reaction Of !Po ·H 2 S04 With Other Nucleophilicmentioning

confidence: 83%

Ionic Oligomerization and Polymerization of 2-Alkenyl-2-oxazolines

Tomalia¹,

Fazio²

1980

Polym J

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ABSTRACT:Ionic RfOpagation of 2-alkenyl-2-oxazolines has been examined in the presence of both cationic and anionic initiators. In order to provide a basis for understanding the cationic (Bmnsted acid) propagation modes, model systems involving 2-alkenyl-2-oxazolinium salts and nucleophiles were studied. Spectroscopic analysis of these salts ( 13 C and 1 H NMR) predicted electrophilic activity at the 2-and 5-position of the heterocyclic ring as well as the terminal olefin carbon. Nucleophilic attack was observed at each of these positions with specificity as a function of the nucleophile type. Ketene aminal species were demonstrated to be key intermediates in the cationic propagation processes as by deuterium trapping experiments. Three new cationic propagation modes leading to dimeric or oligomeric products were identified and occurred as a function of the (a) acid strength, (b) proton multiplicity of the acid, and (c) nucleophilicity of the polymerization medium. Proposed propagation mechanisms ate discussed. Anionic polymerization of 2-isopropenyl-2-oxazoline with butyllithium was shown to give low-molecular-weight polymers which are identical to those obtained by use of radical initiators. Finally, this study demonstrates that whereas radical and anionic polymerization of 2-alkenyl-2-oxazolines involve IXcarbon propagating species, the cationic modes proceed via {3-carbon-type species.

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Section: Reaction Of !Po ·H 2 S04 With Other Nucleophilicmentioning

confidence: 83%

Ionic Oligomerization and Polymerization of 2-Alkenyl-2-oxazolines

Tomalia¹,

Fazio²

1980

Polym J

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“…N-substituted aziridines were synthesized from the correspon ding unsubstituted aziridine (12) or by ring closure of the cor responding 2-amino alcoholsulfate (13). The monomers were distil led from calcium hydride just before use.…”

Section: Methodsmentioning

confidence: 99%

Cationic Polymerization of Cyclic Amines

Goethals¹,

Schacht²,

Bruggeman³

et al. 1977

ACS Symposium Series

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It is now generally accepted that the propagation reaction in the cationic ring-opening polymerization of cyclic amines is a nucleophilic attack of the monomer nitrogen on a strained cyclic ammoni um salt which is the active species of the growing macromolecule. The driving force of the polymerization is the relief of strain associated with the ring-opening of the active chain end. The resultant polymer molecules, however, also contain nucleophilic amino functions and therefore the polymer competes with monomer to react with the active species. This results in the formation of a (linear or cyclic) non-strained and therefore non-reactive ammoni um salt.With secondary cyclic amines (R=H), the proton on the terminated ammoni um salt as well as the proton on the active species can be transferred to other amino groups present in the mixture including monomer. Dimers and other low oligomers are therefore the initial products, and the final products are branched polymers containing a distribution of primary, secondary and tertiary amino functions (1, 2).With cyclic tertiary amines (R = alkyl), the formation of a non-strained ammoni um salt is a real termination reaction. If the rate of this termination reaction is not negligably small compared with the rate of the propagation, in other words if the ratio kp/kt is not very high, the polymerization will stop before 1

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“…NNN'N'-Diethyleneurea and triethylenephosphoramide were prepared using the method described by Bestian (1950). The preparation of di(aziridin-1-yl)sulphoxide has been described previously .…”

Section: Methodsmentioning

confidence: 99%