On the Reactivity of Phosphaalumenes towards C-C Multiple Bonds

Heterocycles containing group 13 and 15 elements such as borazines are an integral part of organic, biomedical and materials chemistry. Surprisingly, heterocycles containing P and Al are rare. We have now utilized phosphaalumenes in reactions with alkynes, alkenes and conjugated double bond systems. With sterically demanding alkynes 1,2-phosphaalumetes were afforded, whereas the reaction with HCCH or HCCSiMe3 gave 1,4-phosphaaluminabarrelenes. Using styrene saturated 1,2-phosphaalumates were formed, which reacted further with additional styrene to give different regio-isomers of 1,4-aluminaphosphorinanes. Using ethylene, a 1,4-aluminaphosphorinane is obtained, while with 1,3-butadiene a bicyclic system containing an aluminacyclopentane and a phosphirane unit was synthesized. The experimental work is supported by theoretical studies to shed light on the mechanism governing the formation of these heterocycles.

Automated summary

Heterocycles containing group 13 and 15 elements play important roles in organic, biomedical, and materials chemistry. However, heterocycles containing P and Al elements are rare. In this study, phosphaalumenes were used to react with alkynes, alkenes, and conjugated double bond systems. Different types of heterocycles, including phosphaalumetes, phosphaaluminabarrelenes, and aluminaphosphorinanes, were synthesized. Experimental work, along with theoretical studies, provided insights into the mechanism of these heterocycle formations.