Ramazanova Kyzgaldak, Müller Anna Karina, Lönnecke Peter, Hollóczki Oldamur, Kirchner Barbara, Hey-Hawkins Evamarie
Institute of Inorganic Chemistry, Faculty of Chemistry and Mineralogy, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany.
Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, Beringstr. 4, 53115 Bonn, Germany.
Molecules. 2023 Oct 19;28(20):7163. doi: 10.3390/molecules28207163.
The reactive P-N bond in 1-phospha-2-azanorbornenes is readily cleaved by simple alcohols to afford -chiral 2,3-dihydrophosphole derivatives as a racemic mixture. The isolation of the products was not possible due to the reversibility of the reaction, which could, however, be stopped by sulfurization of the phosphorus atom, thus efficiently blocking the lone pair of electrons, as exemplified for yielding structurally characterized . Additionally, the influence of the substituent in the α position to the phosphorus atom (H, Ph, 2-py, CN) on the reversibility of the reaction was studied. Extensive theoretical calculations for understanding the ring-closing mechanism suggested that a multi-step reaction with one or more intermediates was most probable.
1-磷杂-2-氮杂降冰片烯中的活性P-N键很容易被简单的醇类裂解，生成外消旋混合物形式的手性2,3-二氢磷杂环戊烯衍生物。由于反应的可逆性，无法分离出产物，不过，通过对磷原子进行硫化可以使反应停止，从而有效地阻断孤对电子，以生成结构表征的产物为例。此外，还研究了磷原子α位上的取代基（H、Ph、2-py、CN）对反应可逆性的影响。为理解闭环机理进行的大量理论计算表明，最可能发生的是有一个或多个中间体的多步反应。
