Spiro[1,2]oxaphosphetanes of Nonstabilized and Semistabilized Phosphorus Ylide Derivatives: Synthesis and Kinetic and Computational Study of Their Thermolysis
作者:Jesús García López、Pablo M. Sansores Peraza、María José Iglesias、Laura Roces、Santiago García-Granda、Fernando López Ortiz
DOI:10.1021/acs.joc.0c01270
日期:2020.11.20
example of an isolated oxaphosphetane having a phenyl substituent at C3 of the ring. Kinetic studies of their thermal decomposition showed that the process takes place irreversibly through a polar transition state (ρ = −0.22) under the influence of electronic, [1,2], [1,3] steric, and solvent effects, with C3/P-[1,2] interactions as the largest contribution to ΔG⧧ of olefination. Inversion of the phosphorus
通过稳定的一系列三和四取代的螺- oxaphosphetanes的邻-苯甲酰胺(Ò BA)和ñ -甲基邻-苯甲酰胺(M ö BA)配位体已经由C的反应,合成α,C邻-dilithiated磷腈与醛和酮。它们包括对映体纯产物和在环的C 3处具有苯基取代基的分离的氧杂膦烷的第一个实例。对它们的热分解的动力学研究表明,在电子,[1,2],[1,3]空间和溶剂效应的影响下,该过程通过极性过渡态(ρ= -0.22)不可逆地发生,C3 / P- [1,2]相互作用是对Δ的最大贡献ģ ⧧烯的。在许多情况下已经观察到通过立体突变使磷构型反转。DFT计算表明,o BA衍生物通过分离的(N,O)(Ph,C 6 H 4,C)氧代磷杂环戊烷(通道A)烯化,而M o BA化合物则通过异构体(C 6 H 4,O)分解得更快由涉及M B2的P-立体突变形成的(C,N,Ph)排列机制(渠道B)。P-异构化的能垒低于烯化的