Study On Acid-promoted Synthesis Of Phosphorothioates,-Selenoates And Phosphinothioates,-Selenoates

We have developed two types methods for preparing phosphorothioates,-selenoates and phosphinothioates,-selenoates promoted by lewis and br?nsted acid and the results are as follows:A one-pot,three-component markovnikov-type addition of terminal alkyne(or alkene),elemental sulfur/selenium,and P–H compounds was developed.This procedure affords valuable?-alkenylphosphorothioates,-selenoates and?-alkylphosphinothioates,-selenoates with broad substrate scope and high regioselectivity.Further mechanistic studies were performed via controlled experiments,such as deuterium labeling experiments,interval NMR and HRMS experiments,to shed light on the mechanism.A plausible radical pathway was outlined on the basis of the results of the experiments and the literature precedents.Alkyl phosphorothioates/phosphoroselenoates were also synthesized from elemental sulfur/selenium,P–H compounds and aliphatic alcohols under solvent-free condition.This simple and efficient one-pot protocol provided an alternative strategy to generate valuable P-chalcogen derivatives from 1~o,2~o,3~o aliphatic alcohols with high efficiency.Moreover,it also worked well for large-scale preparations and synthesis of pesticides,such as Iprobenfos,ethylbenzene benzoate(ESBP)and demeton-S,which effectively avoid the use of traditional halides,-SH and organometallic reagents.