SYNTHESIS AND CYCLIZATION OF PHOSPHORYLATED β-ALLENIC AMINES
摘要:
Phosphorylated beta-allenic amines were obtained by aminophosphorylation of beta-allenic aldehydes and ketones. When treated by silver tetrafluoroborate in methylene chloride, they generated phosphorylated nitrogen cycles such as 1-pyrrolines and 1.2,3,6-tetrahydropyridines, with dephosphorylation of the latter tetrahydropyridines producing 3,6-dihydropyridines.
reaction of allene-tethered dithiosemicarbazides 4 is a convenient method for the preparation of five-membered unsaturated nitrogen heterocycles. The sulfur-directed intermolecular attack of the tin radical at the semicarbazide moiety leads to an allene-tethered iminyl radical, which then undergoes a 5-exo-dig cyclization leading to both the 3H-pyrroles 5 and the alkylidene pyrrolines 6; thermal isomerization
A set of allene-tethered benzoyloximes (5) has been treated with nBu3SnH. Depending on their substitution pattern, a wide range of compounds has been obtained. If the stannyl radical adds on the allene, the C-centred radical thus formed undergoes either a 5-exo ring closure to give the cyclopentene derivatives 7 or a 6-endo ring closure onto the N atom to give the dihydropyridines 8. If the stannyl
一组丙二烯系苯甲酰肟 (5) 已用 nBu3SnH 处理过。根据它们的取代模式,已经获得了广泛的化合物。如果甲锡基自由基加成在丙二烯上,则由此形成的以 C 为中心的自由基经历 5-外环闭合以产生环戊烯衍生物 7 或在 N 原子上进行 6-内环闭合以产生二氢吡啶 8。如果甲锡基自由基添加到苯甲酰基部分,形成亚胺基自由基,导致 3H-吡咯 9 和亚烷基-吡咯啉 10。空间效应和极性效应是控制反应过程的因素。
SYNTHESIS AND CYCLIZATION OF PHOSPHORYLATED β-ALLENIC AMINES
Phosphorylated beta-allenic amines were obtained by aminophosphorylation of beta-allenic aldehydes and ketones. When treated by silver tetrafluoroborate in methylene chloride, they generated phosphorylated nitrogen cycles such as 1-pyrrolines and 1.2,3,6-tetrahydropyridines, with dephosphorylation of the latter tetrahydropyridines producing 3,6-dihydropyridines.