Two Routes for the Synthesis of Phosphorothioates via P‐S Coupling Reaction of Dialkyl Phosphites with Thiols or a Mixture of Alkyl Halides and Thiourea in the Presence of CaO

Abstract

In this report, two routes for the synthesis of phosphorothioates via a P−S cross coupling reaction of thiols with dialkyl phosphites or a three component reaction of alkyl halides, thiourea and dialkyl phosphite in the presence of CaO has been studied. By presented methods, various phosphorothioates are obtained under transition metal‐free condition. The reactions are proceeded with formation of a known intermediate of disulfide via the oxidation of thiols and followed by nucleophilic substitution of dialkyl phosphite with the disulfide intermediate gave phosphorothioate.

ZnCl2-mediated stereo- and chemoselective synthesis of vinylphosphonates

“…22 However, to the best of our knowledge, there are only a few reports on the reaction with methylphosphonates as nucleophilic species in the presence of TiCl 4 / N-methylmorpholine and (i-PrO) 3 TiCl/NaH. 23,24 We recently reported a double hydrophosphonylation of nitriles in the presence of ZnCl 2 /Et 3 N. 25 In continuation of our efforts in developing new synthetic methods for organophosphorous compounds, [26][27][28][29][30][31][32][33] we decided to study the vinylphosphonate-forming reaction using a Lewis acid/base combination. Herein we report an efficient and practical method via the Knoevenagel condensation reaction of carbonyl compounds with cyanomethylphosphonates to yield (E)vinylphosphonates.…”

“…In continuation of our efforts in developing new synthetic methods for organophosphorous compounds, 26–33 we decided to study the vinylphosphonate-forming reaction using a Lewis acid/base combination. Herein we report an efficient and practical method via the Knoevenagel condensation reaction of carbonyl compounds with cyanomethylphosphonates to yield ( E )-vinylphosphonates.…”

Catalyst-Free Synthesis of Phosphorothioates via P–S Coupling ­Reaction of Dialkyl Phosphites with Thiols

“…Recently we have reported a novel basic system for the coupling reaction of thiols with dialkylphosphite for the synthesis of phosphorothioates. 35 According to our information, there is so far no report the synthesis of phosphorothioates by the reaction of thiols with dialkyl phosphites in DMSO without any catalyst. Therefore, we decided that the possibility of using DMSO as an inexpensive and accessible solvent and safe reagent for the synthesis of phosphorothioates in a one-pot way.…”