Design of an Organocatalyst for the Enantioselective Diels−Alder Reaction with α-Acyloxyacroleins
作者:Kazuaki Ishihara、Kazuhiko Nakano
DOI:10.1021/ja053368a
日期:2005.8.1
derived from H-l-Phe-l-Leu-N(CH2CH2)2. The enantioselective Diels-Alder reaction of 5-(benzyloxymethyl)cyclopentadiene, cyclopentadiene, cyclohexadiene, 2,3-dimethylbutadiene, and isoprene with alpha-(p-methoxybenzoyloxy)acrolein catalyzed by the above chiral ammonium salt (2.5-20 mol %) at -20-22 degrees C gave the corresponding adducts with 83, 83, 91, 92, and 88% ee, respectively.
我们已经实现了第一个对映选择性有机催化 Diels-Alder 反应,α 取代的丙烯醛,例如 α-酰氧基丙烯醛,不仅是环状二烯,还包括无环二烯。α-酰氧基丙烯醛可用作α-卤代丙烯醛的合成等价物。本催化剂可由五氟苯磺酸(2.5-3.0当量)和衍生自Hl-Phe-1-Leu-N(CH2CH2)2的手性三胺(1当量)原位制备。5-(苄氧基甲基)环戊二烯、环戊二烯、环己二烯、2,3-二甲基丁二烯和异戊二烯与α-(对甲氧基苯甲酰氧基)丙烯醛在上述手性铵盐(2.5-20 mol %)催化下的对映选择性Diels-Alder反应-20-22 摄氏度产生相应的加合物,分别为 83、83、91、92 和 88% ee。