Application of DMSO in the Synthesis of 1,4-Disubstituted (But-1-en-3-ynyl)methylthioethers

Abstract

DMSO is applied in the methylthiolation of 1,3‐diynes in the presence of formamidine, K3PO4 at 130 °C. This reaction gives 1,4‐disubstituted (but‐1‐en‐3‐ynyl)methylthioethers in good to high yield with acceptable Z/E selectivities. Both (Z)‐ and (E)‐methylthioethers are readily separable. The synthesis of 3‐iodothiophene derevative from (Z)‐methylthoenter is explored as well.

Redox‐Divergent Construction of (Dihydro)thiophenes with DMSO

“…[21] However,there were rare reports that DMSO could be employed as sulfur donor in organic reactions. [22] Herein, we developed ar edox-divergent construction of (dihydro)thiophenes with DMSO as both an oxidant and as ulfur donor. By simply controlling the dosage of HBr and thiophenes and dihydrothiophenes in high selectivity and efficiency.F urthermore,t hrough the further transformation of thiophene and dihydrothiophene products,v arious fivemembered sulfur-containing heterocycles could be readily accessed.…”

Redox‐Divergent Construction of (Dihydro)thiophenes with DMSO

“…[21] However,there were rare reports that DMSO could be employed as sulfur donor in organic reactions. [22] Herein, we developed ar edox-divergent construction of (dihydro)thiophenes with DMSO as both an oxidant and as ulfur donor. By simply controlling the dosage of HBr and DMSO,a llylic alcohols were transformed into valuable Scheme 1.…”

“…Meanwhile, DMSO could also be employed as source of methyl, [16] methine, [17] methylene, [18] methylthio, [19] methylsulfinyl, [20] and oxygen [21] . However, there were rare reports that DMSO could be employed as sulfur donor in organic reactions [22] . Herein, we developed a redox‐divergent construction of (dihydro)thiophenes with DMSO as both an oxidant and a sulfur donor.…”

Application of DMSO as a methylthiolating reagent in organic synthesis

“…Vinyl sulfides, especially 1,4-disubstituted (but-1-en-3-ynyl) methylthioethers, are one of the important intermediates in organic synthesis and have a wide range of applications. In 2017, Zhao and Wang's lab 64 disclosed a methylthiolation reaction to prepare ( Z )-1,4-disubstituted (but-1-en-3-ynyl) methylthioethers 80a from the reaction of 1,3-diynes 79 and DMSO in the presence of formamidine acetate and K 3 PO 4 . It was noted that ( Z )- and ( E )-methyl sulfides could be easily separated by a chromatographic column and ( Z )-methyl sulfides were obtained in fair to high yields.…”