Synthesis and Characterization of Tetraethylethanediselenoamide

Abstract

Tetraethylethanediselenoamide (2) was prepared in 81% yield by reaction of tetraethylethynediamine with elemental selenium. The X-ray single crystal structure analysis revealed that two Et2N(C=Se)– units of 2 are perpendicular to each other. The oxidation of 2 with m-CPBA produced tetraethylmonoselenooxamide and the reaction with DMAD afforded dimethyl 4,5-bis(diethylamino)selenophene-2,3-dicarboxylate.

Synthesis of Pentathiepanes and Isolation of the Conformers Based on High Inversion Barrier of the Pentathiepane Ring

“…It is also much longer than the corresponding CϪC bond length of the previously reported 6-spectrum of the reaction mixture did not show any signals that indicate the presence of the ethyl group, probably betrimethylsilyl-1,2,3,4,5-pentathiepane (6, 1.52 Å ) that exists in a twist-boat conformation. [10] Also noteworthy is that cause the reaction of 7 with sulfur took place much faster at the benzylic position than at the CϭC bond. [20] the S(1)ϪC(1)ϪC(naph2) and S(5)ϪC(2)ϪC(naph4) bond angles of 112.9°and 113.0°, are much larger than The above unsuccessful results prompted us to introduce a phenyl group, rather than an alkyl group, into 2.…”

A Convenient Method for the Generation of a Disulfur Monoxide Equivalent and Its Reaction with Diazoalkanes to Yield Dithiirane 1-Oxides

“…The mixture was subjected to mediumpressure liquid chromatography (SiO 2 , hexane/Et 2 O 4/1) to give 8 (11 mg, 0.047 mmol, 17 % based on DMD), 9 (71 mg, 0.185 mmol), and 10 (26 mg, 0.073 mmol). Method II: A solution of 5-(1-adamantyl)-5-(tert-butyl)tetrathiolane (22) [1,23] (33 mg, 0.10 mmol) in dichloromethane (8 mL) was treated with DMD (0.40 mmol) at À 20 8C. The mixture was stirred for 1.5 h at À 20 8C and then the solvent was removed under reduced pressure.…”

“…We also investigated the reaction of S 2 O with diazoalkanes, which provides an alternative method for the preparation of dithiirane derivatives. [22]…”

Synthesis of Selenophenes

“…Nakayama [85] and coll. reported the preparation of an intermediate tetraethylethanediselenoamide 33 in 81% and its reaction with DMAD in refluxing chlorobenzene, followed by the thermal extrusion of selenium to produce dimethyl 4,5-bis(diethylamino)selenophene-2,3-dicarboxylate 35 in 87%.…”