Synthesis of Novel Gemini Dicationic Acidic Ionic Liquids and Their Catalytic Performances in the Beckmann Rearrangement

✍ Scribed by Xiaofei Liu; Linfei Xiao; Hugjiltu Wu; Jing Chen; Chungu Xia

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: German
• Weight: 189 KB
• Volume: 92
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200800382

✦ Synopsis

Abstract

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A series of novel gemini dicationic acidic ionic liquids (GDAILs), compounds 1–3 carrying two SO~3~H groups at the cation moieties and having anions of the type CF~3~SO$\rm{ _3^ - }$, were synthesized in good yields (Scheme 1). Some physicochemical properties of 1–3 were determined; due to their unique structures, these novel GDAILs showed noticeable hydrophilic properties and strong acidities (Table 1). Beckmann rearrangements of oximes catalyzed by 1, 2, or 3/zinc chloride (GDAIL/ZnCl~2~) were investigated (Scheme 2); the corresponding amides were formed in up to 99% yield in the presence of 5 mol‐% of GDAIL/ZnCl~2~ catalyst under optimized conditions (Tables 2 and 3). The peculiar solubilities of 1–3 made the separation of the catalysts from the products very facile, and the catalytic system could be recycled and reused for three times.