Priebe, Hanno, Acta chemica Scandinavica. Series B: Organic chemistry and biochemistry, 1987, vol. 41, # 9, p. 640 - 645
作者:Priebe, Hanno
DOI:——
日期:——
Synthesis and Reactivity of Electron-Poor 2-Azadienes. [4 + 2] Cycloaddition Reactions with Alkenes and Enamines
作者:Francisco Palacios、Itziar Perez de Heredia、Gloria Rubiales
DOI:10.1021/jo00113a017
日期:1995.4
Electron deficient 2-azadienes derived from beta-amino acids 3 are obtained by aza-Wittig reaction of N-vinylic phosphazenes 4 with carbonyl compounds. Inverse electron demand Diels-Alder reaction of azadienes 3 with trans-cyclooctene 7 and cis,trans-cyclooctadiene 8 leads to the formation of trans-cycloalkanotetrahydropyridines 10. Heterodienes 3 also react with enamines 13, 14, and 18 affording pyridine derivatives 16, 17, and 20 in a regioselective fashion. Norbornadiene 11, a less strained olefin than cycloalkenes 7 and 8, requires the presence of lithium perchlorate as catalyst in a nonaqueous solvent like ether, to give cycloadducts 12.
Preparation and reactivity of electron-poor 2-azadienes. Diels-Alder reaction with trans-cyclooctene.
作者:Francisco Palacios、Itziar Perez de Heredia、Gloria Rubiales
DOI:10.1016/s0040-4039(00)79357-9
日期:1993.7
Di-, tri- and tetra- substituted 2-azadienes 3 underbar with electron withdrawing groups have been obtained by Aza-Wittig reaction of N-vinylic phosphazenes with carbonyl compounds. The Diels-Alder reaction of 3 underbar with trans-cyclooctene has also been explored.
Reactivity of Conjugated Phosphazenes Derived from Dehydroaspartic Esters with Acyl Halides. Synthesis of 5(4H)-Oxazolone
作者:Francisco Palacios、Marta Legido、Itziar Perez de Heredia、Gloria Rubiales
DOI:10.3987/com-99-s130
日期:——
The reactivity of N-vinylic phosphazenes derived from dehydroaspartic esters towards acyl halides is reported. Treatment of conjugated phosphazene with acyl halides led to the formation of N-acylated dehydroaspartic esters and alkenyl-5(4N)-oxazolones. When the reaction was performed in the presence of diethylamine, 1-diethylamino-3,4-dimethoxycarbonyl-2-aza-1,3-butadiene was obtained. Reaction of substituted 5(4H)-oxazolones with water, ethanol and amines gave N-acylated dehydroaspartic acid derivatives.
PRIEBE, HANNO, ACTA CHEM. SCAND., 41,(1987) N 9, 640-645