Water-Soluble Calixarenes as New Inverse Phase-Transfer Catalysts. Their Scope in Aqueous Biphasic Alkylations and Mechanistic Implications

✍ Scribed by Shoichi Shimizu; Takashi Suzuki; Seiji Shirakawa; Yasuyuki Sasaki; Choichiro Hirai

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 121 KB
• Volume: 344
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/1615-4169(200206)344:3/4<370::aid-adsc370>3.0.co;2-3

✦ Synopsis

Alkylation reactions of active methylene compounds, alcohols and phenols with alkyl halides in aqueous NaOH solution can be carried out without the need for any added organic solvents in most cases. The water-soluble calix[n]arenes, which contain trimethylammoniomethyl groups on the upper rim, were used as inverse phase-transfer catalysts, result-ing in the corresponding alkylated products in good to high yields. The scope of this methodology in aqueous biphasic alkylation reactions and the mechanistic implications are discussed.