Synthesis of Dihydrothiophene, Thiophene, and Their Selenium Analogues Carrying Four Phosphoryl Groups

Abstract

[reaction: see text] Sodium hydrosulfide undergoes addition to two molecules of bis(diethoxyphosphoryl)acetylene followed by cyclization to give a 2,3-dihydrothiophene carrying four phosphoryl groups. Oxidation of the 2,3-dihydrothiophene with mCPBA gives the corresponding sulfoxide or sulfone depending on the ratio of the reagents, and the sulfoxide is dehydrated to afford a tetraphosphorylthiophene. The corresponding dihydroselenophene and selenophene are also synthesized in a similar manner.

Reversible oxidation of a water-soluble tellurophene

“…meta-Chloroperoxybenzoic acid (mCPBA) reacts with thiophenes to give sulfoxide when reacted stoichiometrically and sulfones when reacted in excess, 11 and thus can be used to further probe the identity of the oxidized products. A solution of 1 exposed to 1 equivalent of mCBPA in dichloromethane yields 2.…”

Synthesis of Functionalized Thiophenes by Four‐component Reactions of 1,3‐Thiazolidinedione, Aromatic Aldehydes, Cyanoacetamide and Cyclic Secondary Amines

“…[1][2][3][4] Though various methods for preparation of thiophenes have been established, the elaboration of the existing thiophene skeleton with multiple substituents at the specific positions is still a challenging work. [5][6][7][8][9][10][11] Gewald's reaction might be one of the most convenient and well-established method for preparing polysubstituted thiophenes which involves multicomponent reaction of a ketone, an activated nitrile with elemental sulfur in the presence of base catalyst. [12][13][14] In the past two decades, multicomponent reaction has become one of the most attractive synthetic method because they offer significant advantages over conventional linear-step syntheses due to their flexible, convergent and atom efficient nature.…”

Thiophenes, Thiophene 1,1-Dioxides, and Thiophene 1-Oxides (Update 2011)

“…[36] Scheme 1 Synthesis of a Tetraphosphorylthiophene [36] (EtO) 2 P (EtO) 2 trans-2,3,4,5-Tetrakis(diethoxyphosphoryl)-2,3-dihydrothiophene (2): [36] A mixture of acetylene 1 (1.87 g, 6.27 mmol) and NaSH • xH 2 O (198 mg) in Et 2 O (5 mL) was stirred for 12 h at 20 8 8C. [36] Scheme 1 Synthesis of a Tetraphosphorylthiophene [36] (EtO) 2 P (EtO) 2 trans-2,3,4,5-Tetrakis(diethoxyphosphoryl)-2,3-dihydrothiophene (2): [36] A mixture of acetylene 1 (1.87 g, 6.27 mmol) and NaSH • xH 2 O (198 mg) in Et 2 O (5 mL) was stirred for 12 h at 20 8 8C.…”

“…2,3,4,5-Tetrakis(diethoxyphosphoryl)thiophene (4): [36] A soln of MCPBA (65%; 74.9 mg, 0.280 mmol) in CH 2 Cl 2 (1 mL) was added to a soln of 2,3-dihydrothiophene 2 (148 mg, 0.235 mmol) in CH 2 Cl 2 (2 mL) at 0 8 8C. The mixture was stirred at 0 8 8C for 1 h and then at 20 8 8C for 1.5 d. The mixture, which consisted mainly of trans-2,3,4,5-tetrakis(diethoxyphosphoryl)-2,3-dihydrothiophene S-oxide (3), was directly submitted to column chromatography (silica gel, EtOAc/acetone) to give 4 as a colorless oil; yield: 78.5 mg (53%).…”