Heift Dominikus, Benkő Zoltán, Suter Riccardo, Verel René, Grützmacher Hansjörg
Department of Chemistry and Applied Biosciences , ETH Zurich , CH-8093 Zurich , Switzerland . Email:
Budapest University of Technology and Economics , H-1111 Budapest , Hungary.
Chem Sci. 2016 Sep 1;7(9):6125-6131. doi: 10.1039/c6sc01269h. Epub 2016 Jun 17.
The reaction of Na(OCP) with mesitoyl chloride delivers an ester functionalized 1,2,4-oxadiphosphole in a clean and P-atom economic way. The reaction mechanism has been elucidated by means of detailed NMR-spectroscopic, kinetic and computational studies. The initially formed acyl phosphaketene undergoes a pseudo-coarctate cyclization with an (OCP) anion under the loss of carbon monoxide to yield a five-membered ring anion. Subsequently, the nucleophilic attack of the formed heterocyclic anion on a second acyl chloride molecule results in the 1,2,4-oxadiphosphole. The transient acyl phosphaketene is conserved during the reaction in the form of four-membered ring adducts, which act as a reservoir. Consequently, the phosphaethynolate anion has three different functions in these reactions: it acts as a nucleophile, as an en-component in [2 + 2] cycloadditions and as a formal P transfer reagent.
Na(OCP) 与均三甲酰氯反应能以一种简洁且磷原子经济的方式生成酯官能化的1,2,4-氧杂二磷杂环戊二烯。通过详细的核磁共振光谱、动力学和计算研究阐明了该反应机理。最初形成的酰基磷杂乙酮在一氧化碳损失的情况下与 (OCP) 阴离子发生假缩环环化反应，生成一个五元环阴离子。随后，所形成的杂环阴离子对第二个酰氯分子进行亲核进攻，从而生成1,2,4-氧杂二磷杂环戊二烯。瞬态酰基磷杂乙酮在反应过程中以四元环加合物的形式得以保留，这些加合物起到了储存库的作用。因此，磷乙炔醇盐阴离子在这些反应中具有三种不同的功能：它作为亲核试剂、作为 [2 + 2] 环加成反应中的烯组分以及作为形式上的磷转移试剂。
