Negretti Solymar, Cohen Carolyn M, Chang Jane J, Guptill David M, Davies Huw M L
Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, USA.
Tetrahedron. 2015 Sep 30;71(39):7415-7420. doi: 10.1016/j.tet.2015.05.045. Epub 2015 Jun 2.
Highly functionalized cyclopropanecarboxylates were readily prepared by rhodium-catalyzed cyclopropanation of alkenes with aryldiazoacetates and styryldiazoaceates, in which the ester functionality is either trimethylsilylethyl (TMSE) or trichlorethyl (TCE). By having labile protecting groups on the ester, chiral triarylcyclopropane carboxylate ligands were conveniently prepared. The asymmetric induction during cyclopropanation is dependent on the nature of the ester group and the chiral dirhodium tetracarboxylate catalyst. The prolinate catalyst Rh(-DOSP) was the optimum catalyst for asymmetric intermolecular cyclopropanation of TMSE diazoesters with styrene, while Rh(-BPCP) was the optimum catalyst for TCE diazoesters.
通过铑催化烯烃与芳基重氮乙酸酯和苯乙烯基重氮乙酸酯的环丙烷化反应，可轻松制备高度官能化的环丙烷羧酸酯，其中酯官能团为三甲基硅乙基（TMSE）或三氯乙基（TCE）。通过在酯上具有不稳定的保护基团，可方便地制备手性三芳基环丙烷羧酸酯配体。环丙烷化过程中的不对称诱导作用取决于酯基的性质和手性四羧基二铑催化剂。脯氨酸催化剂Rh(-DOSP)是TMSE重氮酯与苯乙烯进行不对称分子内环丙烷化反应的最佳催化剂，而Rh(-BPCP)是TCE重氮酯的最佳催化剂。
