An allo-threonine-derived O-(p-biphenylcarbonyloxy)-B-phenyl-oxazaborolidinone is demonstrated to be a powerful and highly enantioselective Lewis acid catalyst for the enantioselective Diels–Alder reaction of simple acyclic enone dienophiles, expanding the scope of ketone dienophiles and dienes. With 10–20 mol % of the catalyst, the Diels–Alder adducts are obtained with up to 94 % ee and high endo
异苏
氨酸衍生的 O-(对
联苯羰基氧基)-B-苯基-氧杂
硼烷酮被证明是一种强大且高度对映选择性的
路易斯酸催化剂,用于简单无环烯酮亲二烯体的对映选择性 Diels-Alder 反应,扩大了酮双烯体的范围和二烯。使用 10-20 mol % 的催化剂,Diels-Alder 加合物可达到 94% ee 和高内选择性。该催化剂在与反应性较低的β-取代亲二烯体和反应性较低的
1,3-环己二烯和
1,3-丁二烯衍
生物的反应中表现出高活性。(© Wiley-
VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)