Michaelis–Arbuzov reaction

The Michaelis–Arbuzov reaction (also called the Arbuzov reaction) is the chemical reaction of a trivalent phosphorus ester with an alkyl halide to form a pentavalent phosphorus species and another alkyl halide. The picture below shows the most common types of substrates undergoing the Arbuzov reaction; phosphite esters (1) react to form phosphonates (2), phosphonites (3) react to form phosphinates (4) and phosphinites (5) react to form phosphine oxides (6).

Source: Wikipedia — Michaelis–Arbuzov reaction (CC BY-SA 4.0)