9-Fluorenylphosphines for the Pd-Catalyzed Sonogashira, Suzuki, and Buchwald–Hartwig Coupling Reactions in Organic Solvents and Water
作者:Christoph A. Fleckenstein、Herbert Plenio
DOI:10.1002/chem.200601142
日期:2007.3.16
lithiation and reaction with R2PCl (R=Cy, iPr, tBu) generates 9-alkyl, 9-PR2-fluorenes which constitute electron-rich and bulky phosphine ligands. The in-situ-formed palladium-phosphine complexes ([Na2PdCl4], phosphonium salt, base, substrates) were tested in the Sonogashira, Suzuki, and Buchwald-Hartwig reactions of aryl chlorides and aryl bromides in organic solvents. The Sonogashira coupling of aryl chlorides
芴的锂化/烷基化导致各种9-烷基芴(烷基= Me,Et,iPr,-Pr,-C18H25)> 95%的收率,对此进行锂化和与R2PC1的反应(R = Cy,iPr,tBu )生成9-烷基,9-PR2-芴,它们构成了富电子且庞大的膦配体。在有机溶剂中的芳基氯化物和芳基溴化物的Sonogashira,Suzuki和Buchwald-Hartwig反应中测试了原位形成的钯-膦配合物([Na2PdCl4] 、,盐,碱,底物)。在1-mol%的Pd催化剂下,在100-120摄氏度下,芳基氯化物的Sonogashira偶联可导致> 90%的收率。芳基氯的Suzuki偶联通常需要在100摄氏度的二恶烷中加入0.05摩尔%的Pd催化剂,以定量形成产物。为了在水中进行“绿色”交叉偶联反应,使9-乙基芴基二环己基膦在硫酸中反应,生成相应的2-磺化phospho盐。通过使用这种水溶性催化剂进行的活化芳基氯的Suzuki偶联仅需要0