Synthesis of 4-sulfonatobenzylphosphines and their application in aqueous-phase palladium-catalyzed cross-coupling
作者:Jane N. Moore、Nicholas M. Laskay、Kevin S. Duque、Steven P. Kelley、Robin D. Rogers、Kevin H. Shaughnessy
DOI:10.1016/j.jorganchem.2014.11.011
日期:2015.2
readily separated from organic products and potentially reused. The synthesis of two new water-soluble ligand precursors, di-tert-butyl(4-sulfonatobenzyl)phosphonium and di-1-adamantyl(4-sulfonatobenzyl)phosphonium, are reported. The air-stable, zwitterionic phosphonium salts were prepared by the reaction of dialkylphosphines with ethyl 4-bromomethylbenzenesulfonate, which results in a one-pot alkylation
水双相催化为更安全,更环境可持续的合成工艺提供了潜力。另外,亲水性支撑配体允许均相催化剂容易地与有机产物分离并潜在地重复使用。两个新的水溶性配体前体的合成,二-叔报道了丁基(4-磺酰基苄基)phosph和二-1-金刚烷基(4-磺酰基苄基)phosph。通过二烷基膦与4-溴甲基苯磺酸乙酯的反应制备空气稳定的两性离子ethyl盐,其导致一锅烷基化,然后使磺酸乙酯脱保护。该方法提供了比亲电磺化更容易操作的方法来磺化苄基膦。将新的膦配体应用于芳基溴化物的水相Suzuki和Sonogashira偶联。