PhP=CPh
<sub>2</sub>
and Related Phosphaalkenes: A Solution Equilibrium between a Phosphaalkene and a 1,2‐Diphosphetane
作者:Shuai Wang、Kerim Samedov、Spencer C. Serin、Derek P. Gates
DOI:10.1002/ejic.201600599
日期:2016.9
The synthesis of phosphaalkenes, ArP=C(R)Ph (1, a: Ar = Ph, R = Ph; b: Ar = o-Tol, R = Ph; c: Ar = Mes, R = H), bearing sterically less hindered substituents is reported. Phosphaalkenes 1a–b were prepared by treating Ph2C=O with ArP(Li)SiMe3, whereas 1c was accessed from the AlCl3-mediated reaction of ArP(SiMe3)2 and PhC(O)H. Both 1a and 1b dimerize to afford their respective 1,2-diphosphetanes (2a
磷烯烃的合成,ArP=C(R)Ph(1,a:Ar=Ph,R=Ph;b:Ar=o-Tol,R=Ph;c:Ar=Mes,R=H),空间位阻较少受阻取代基的报道。磷烯烃 1a-b 是通过用 ArP(Li)SiMe3 处理 Ph2C=O 制备的,而 1c 是通过 AlCl3 介导的 ArP(SiMe3)2 和 PhC(O)H 的反应获得的。1a 和 1b 均二聚化以提供各自的 1,2-二膦烷(2a 和 2b)。化合物 2a 通过 X 射线晶体学表征。纯 2a 在 THF 中的溶解导致与单体 1a 的温度相关平衡(ΔHo = –94.6 ± 14.6 kJ mol–1;ΔSo = –284 ± 48 J mol–1 K–1)。尽管单体 E/Z-1c 在溶液中通过其特征性的低场 31P NMR 化学位移(δ = 247.1, 231.5)被鉴定出来,但伴随着我们认为是低聚物的形成(δ = –25 到 10