introducing a tolyl or phenyl ligand at the apical position, respectively, via the S(E)Ar mechanism, and they were found to be efficient catalysts for cis-selective asymmetric cyclopropanation. The scope of the cyclopropanation was wide, and the reactions of not only conjugated mono-, di-, and trisubstituted olefins but also nonconjugated terminal olefins proceeded with high enantio- and cis-selectivity
通过 S(E)Ar 机制分别在顶端引入
甲苯基或苯基
配体,合成了两种稳定且具有旋光活性的
铱-salen 配合物,发现它们是顺式选择性不对称
环丙烷化的有效催化剂。
环丙烷化的范围很广,不仅共轭单、二、三取代烯烃的反应,而且非共轭末端烯烃的反应都具有很高的对映选择性和顺式选择性,即使在存在官能团如醚或酯。8-[(1R,2S)-2-己基环丙基]
辛酸酯的短步合成证明了该
环丙烷化的效用,该合成从大肠杆菌B-A
TCC 11303中分离,使用该反应作为关键步骤。