Commonly used reagents—-diethyl phosphite_industrial additives

Under the action of a strong base, DEP can form negative ions, which can undergo nucleophilic substitution reactions with halogenated compounds (such as those made from alcohols). A variety of phosphonates (Formula 1)[1~4] can be synthesized using this method.

Under the catalysis of transition metal complexes [such as Pd(PPh3)2, Pd(PPh3)4], DEP can catalyze halogenated aromatic compounds [5~7], halogenated alkenes [8,9], and alkynes [ 10] reacts to form phosphonate ester. During the reaction, palladium is inserted into the middle of the carbon-halogen bond and forms a complex with phosphorus, and then the phosphorus is transferred to the carbon to form a phosphonate ester (formula 2) [5].

In the presence of a strong base, the negative ions formed by DEP can undergo nucleophilic addition reactions with unsaturated bonds such as aldehydes (formula 3) [11,12] and imines [13,14] to obtain phosphonate esters compounds. It should be noted that both reaction rate and reaction yield are affected by steric hindrance. Some of these reactions [13,14] can achieve good stereoselectivity under the induction of chiral ortho groups.

In the presence of free radical initiators, DEP can also react with unsaturated compounds such as imines (Formula 5) [17] to obtain phosphonate esters.

In the presence of CCl4 and N(Et)3, DEP can react with amines to form amine phosphate (Formula 6) [18]. This reaction can be carried out in the aqueous phase. The reaction proceeds through the formation of a P-Cl bond intermediate, followed by the attack of the amine as a nucleophile on the phosphorus atom.