A Convenient Preparation of Sterically Crowded 1,9-Disubstituted Dibenzothiophenes and 3,3'-Disubstituted Diaryl Sulfides
摘要:
Thianthrene-5-oxide (1) reacted with 2.2 equivalents of lithium diisopropylamide to give 4,6-dilithiated 1 which was converted to 4,6-disubstituted thianthrene-5-oxides (3). 3 afforded sterically crowded 1,9-disubstituted dibenzothiophenes (4) in moderate yields on treatment with n-butyllithium or phenyllithium.
Asymmetric Oxidation of 1,9-Bis(methylthio)dibenzothiophene and First Determination of Optically Active<i>l</i>-Menthoxy Sulfonium Salt by X-Ray Crystallographic Analysis
l-Menthoxy sulfonium salt of 1,9-bis(methylthio)dibenzothiophene was isolated, and the structure was first determined by X-ray crystallographic analysis.
分离出1,9-双(甲硫基)二苯并噻吩的l-薄荷氧基锍盐,并首先通过X射线晶体分析确定了其结构。
First preparation of dibenzo[bc,fg][1,4]dithiapentalene and determination of the structure by X-ray analysis
New stable dibenzo[bc,fg][1,4]dithiapentalene (1) was prepared by heating 1,9-bis(methylthio)-dibenzothiophene in a glass tube. The X-ray analysis of 1 reveals clearly that it has a completely planar structure. Repeated scanning of cyclic voltammetry of 1 shows an analogous voltammogram with that of polythiophene.
1,9-Dithiodibenzothiophenes 2 were prepared by ring contraction of 4,6-dithiothianthrene-5-oxides with n-butyllithium. Both compounds 2 and their monooxides 3 upon dissolution in conc. H2SO4 afforded the corresponding new dithia dications. Electrochemical oxidation of 2 provides the evidence for the neighboring group interaction between the two 1,9-sulfenyl sulfur atoms.