Reactivity of Conjugated Phosphazenes Derived from Dehydroaspartic Esters with Acyl Halides. Synthesis of 5(4H)-Oxazolone

Preparation of 3‐(Fluoroalkyl)‐2‐azadienes and Its Application in the Synthesis of (Fluoroalkyl)isoquinoline and ‐pyridine Derivatives

“…The configuration of the vinylic double bonds was determined on the basis of heteronuclear 19 F– 1 H HOESY experiments which showed cross signals between fluorinated groups and vinylic protons suggesting the formation of the ( Z ) isomer (Table 1, entries 2, 4 and 6). Similar isomerization reactions have been observed previously by us16 and by others 17…”

Synthesis of Aza Polycyclic Compounds Derived from Pyrrolidine, Indolizidine, and Indole via Intramolecular Diels−Alder Cycloadditions of Neutral 2-Azadienes

“…The starting phosphazene being a mixture of isomers 3E/3Z (70/30),3d only evidence of (1 E ,3 E )-azadiene 5e was detected ( J = 7 Hz). This observation could be explained by an isomerization of the vinylic double bond through an ionic intermediate . However, azadiene 5f containing a methyl group in the 4-position and obtained from a mixture of isomers 3 E /3 Z of phosphazene 1f 3d delivered one isomer corresponding to each isomer of the starting material, affording a mixture of 1 E ,3 Z /1 E ,3 E azadienes 5f in proportion similar to those presented in the precursor phosphazene 1f (Table , entry 9).…”

“…This observation could be explained by an isomerization of the vinylic double bond through an ionic intermediate. 15 However, azadiene 5f containing a methyl group in the 4-position and obtained from a mixture of isomers 3E/3Z of phosphazene 1f 3d delivered one isomer corresponding to each isomer of the starting material, affording a mixture of 1E,3Z/1E,3E azadienes 5f in proportion similar to those presented in the precursor phosphazene 1f (Table 1, entry 9). Polycyclic compounds 6a-f were obtained when azadienes 5a-f were heated at xylene reflux temperature (Table 1, entries 10-15) and were compared with those corresponding to the polyheterocycles 6a-c obtained from 2-allyloxybenzaldehyde 2 (Table 1, entries 10-12).…”

“…(1E,3Z)-3-(2-Furyl)-4-phenyl-1-(N-allyl-2-pyrrolyl)-2azabuta-1,3-diene (15). The general procedure was followed using 1,1,1,4-tetraphenyl-3-(2-furyl)-2-aza-1λ 5 -phosphabuta-1,3-diene (2.225 g) and 1-(N-allyl)pyrrolecarboxaldehyde 12 (0.675 g) in toluene.…”

N-Vinylic Phosphazenes. A Useful Tool for the Synthesis of Acyclic and Heterocyclic Compounds

“…The reactivity of conjugated phosphazene 37 derived from dehydroaspartic ester with acyl halides has been studied (Scheme 16) [25]. Reaction of phosphazene 37 with acyl halides afforded N-acylated dehydroaspartic ester derivatives 39, azadienes 41, and 4-methylidene-5(4H)-oxa- This approach has been used for an elegant synthesis of the bis(indole) marine alkaloid rhopaladin D 47 which has …”