Stereoselective synthesis of trans N/O dispirocyclic cyclotriphosphazenes based on the steric demands of the constrained 2-pyridyl group
作者:Kazumasa Kajiyama、Masataka Suzuki、Masanori Kojima、Yuki Setone
DOI:10.1016/j.inoche.2013.07.016
日期:2013.9
hexachlorocyclotriphosphazene, N3P3Cl6 (1), with 2-(2-pyridylamino)phenol in the presence of base. The reactions of phosphazenes 2a and 2b with sodium (4-methyl-2-pyridyl)oxide afforded tetrakis- and bis(4-methyl-2-pyridyloxy)cyclotriphosphazenes, 3a and 3b, respectively. 31P NMR spectroscopy of 2b and 3b using d-camphorsulfonic acid as a chiral solvating agent indicated that they were racemates of the trans
摘要 通过六氯环三磷腈 N3P3Cl6 (1) 与 2-(2-吡啶氨基)苯酚在碱存在下的反应合成了单螺环和双螺环环三磷腈 2a 和 2b。磷腈 2a 和 2b 与(4-甲基-2-吡啶基)氧化钠的反应分别得到四-和双(4-甲基-2-吡啶氧基)环三磷腈,3a 和 3b。使用d-樟脑磺酸作为手性溶剂化剂的2b和3b的31P NMR光谱表明它们是反式异构体的外消旋体。trans-3b 的反式构型也可以通过 X 射线晶体结构分析阐明,这表明 2-吡啶基的空间需求是造成 trans-2b 立体选择性形成的原因。N3P3Cl6 (1) 与 N 的反应支持了 2-吡啶基的空间需求,