Improved Asymmetric S<sub>N</sub>Ar Reaction of β-Dicarbonyl Compounds Catalyzed by Quaternary Ammonium Salts Derived from Cinchona Alkaloids
作者:Sara Kobbelgaard、Marco Bella、Karl Anker Jørgensen
DOI:10.1021/jo060627l
日期:2006.6.1
limitation of the asymmetric nucleophilic aromatic substitution reaction of α-substituted 1,3-dicarbonyl compounds and activated aromatic systems catalyzed by N-benzyl-O-benzoylcinchoninium or cinchonidinium salts are presented. Several novel O-benzoylcinchona alkaloid derived salts have been prepared and evaluated as catalysts in this reaction, which can proceed with enantioselectivites up to 96% ee. Various
提出了α-取代的1,3-二羰基化合物与N-苄基-O-苯甲酰基金鸡鎓盐或金鸡啶鎓盐催化的活化芳族体系的不对称亲核芳族取代反应的范围和局限性。几本新颖的O已经制备了-苯甲酰金鸡纳生物碱衍生的盐,并在该反应中作为催化剂进行了评估,该盐可以进行对映体选择性高达ee达96%的反应。评价了各种1,3-二羰基化合物和活化的芳族体系用于芳族亲核取代反应,并且发现产率和对映选择性非常依赖于底物和试剂。产物官能化为例如螺-氧代吲哚,1,3α,α-二取代的二羰基化合物与几种亲核试剂的开环反应以及旋光性S N中非对映选择性降低酮官能度的范围报告了Ar产品。