Brown Laboratories, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
J Am Chem Soc. 2013 Jun 26;135(25):9283-6. doi: 10.1021/ja403811t. Epub 2013 Jun 12.
Enantiomerically enriched cyclobutanes are constructed by a three-component process in which t-butyl (E)-2-diazo-5-arylpent-4-enoates are treated with Rh2(S-NTTL)4 to provide enantiomerically enriched bicyclobutanes, which can subsequently engage in homoconjugate addition/enolate trapping sequence to give densely functionalized cyclobutanes with high diastereoselectivity. This three-component, two-catalyst procedure can be carried out in a single flask. Rh2(S-NTTL)4-catalyzed reaction of t-butyl (Z)-2-diazo-5-phenylpent-4-enoate gives the Büchner cyclization product in excellent enantioselectivity.
通过三组分过程构建对映体富集的环丁烷，其中叔丁基（E）-2-重氮-5-芳基戊-4-烯酸酯与 Rh2（S-NTTL）4 反应，提供对映体富集的双环丁烷，随后可以进行同共轭加成/烯醇化物捕获序列，以高非对映选择性得到高度官能化的环丁烷。这个三组分、双催化剂的程序可以在一个单一的烧瓶中进行。叔丁基（Z）-2-重氮-5-苯基戊-4-烯酸酯的 Rh2（S-NTTL）4 催化反应以优异的对映选择性得到 Büchner 环化产物。
