110700-09-9Relevant academic research and scientific papers
Cycloadditions, 16. - Influence of Alkyl and Phenyl Groups in the Allenic ω-Position on the Intramolecular Diels-Alder Reactions of Allene Carbamides
Himbert, Gerhard,Diehl, Klaus,Schlindwein, Hans-Juergen
, p. 1691 - 1700 (2007/10/02)
The influences of methyl (partly of other alkyl) and phenyl moieties in the allenic ω-position on the isomerization tendencies of the N-phenyl- and N-(α-naphthyl)allenecarboxamides (5, 6 and 7, 8, resp.) are investigated.Methyl groups always decelerate (5, 7, 8 -> 9, 10, 11a-c), phenyl groups hinder (5f -> 9f and 12f), prevent (5, 6g), or accelerate (7f,g, 8g -> 10f,g, 11g) the intramolecular Diels-Alder reactions.The diphenyl compounds 5g, 6g cyclize to give the quinolones 12, 13; if this cyclization is prevented by two methyl groups in the ortho positions (s. 15), the common dimerization of allenes takes place to give the cyclobutane derivative 17. - Key Words: Allenecarboxamides/ Diels-Alder reaction/ Dimerization
Cycloadditions, 12. - Influence of Aromatic Alkyl Groups on the Intramolecular Diels-Alder Reaction of Aryl Allenecarboxylates and of Allenecarboxanilides
Himbert, Gerhard,Fink, Dieter,Diehl, Klaus
, p. 431 - 442 (2007/10/02)
The aryl allenecarboxylates 4a-o and the allenecarboxanilides 9a, b, e, h, and l, which differ from one another only by the number or by the size of the alkyl groups attached to the arene, are synthesized by the ylide method via the appropriately substituted 2-halo-, 2-phosphonio-, and 2-phosphoranylideneacetic acid derivatives (1-->2-->3-->4 and 6-->7-->8-->9, resp.).By refluxing in xylene they are transformed into the tricyclic compounds 5 and 10; the rates and their differences are discussed.
