were obtained (Table 2). Usually, the reactions were carried out using bis(semicorrinato)copper(II) complexes as precatalysts. In order to produce active catalysts, these complexes had to be activated first by heating in the presence of diazoacetate or by treatment with phenylhydrazine. Experiments with (semicorrinato)copper(I) complexes, prepared in situ from copper(I) tert-butoxide (Scheme 4), suggest
发现手性,C 2对称半corrin
配体的
铜配合物是从烯烃与重氮化合物形成
环丙烷的有效催化剂。在催化剂的1%模式下,
重氮乙酸烷基酯与末端烯烃如
苯乙烯,
丁二烯和
1-庚烯平稳地反应,得到相应的光学活性
环丙烷羧酸衍
生物(表1方案2)。使用其中一种催化剂,对映选择性高达97%ee (表2)。通常,该反应使用双(准corrinato)
铜(II)配合物作为预催化剂进行。为了生产活性催化剂,必须首先通过在
重氮乙酸酯存在下加热或通过苯
肼处理来活化这些配合物。使用由
叔丁醇铜(I)原位制备的(semicorrinato)
铜(I)配合物进行的实验(方案4)表明,实际的催化剂是[单(semicorrinarinato)]
铜(I)。