Synthesis and characterisation of severely hindered P-OR compounds

P-Cl substrates were converted into their P-OR analogues from hindered alcohols using an amine base. Where the system was severely hindered, more forcing conditions were required that necessitated the presence of a metal alkoxide nucleophile before successful reactions were observed. In some instances, the products were thermally unstable and reverted to alkenes by elimination reactions, while others were sensitive to moisture. Here, hydrolysis products prevailed if moisture was not rigorously excluded. Details are presented to obtain the P(III) and P(V) esters, diesters and half esters.