Department of Chemistry, University of South Florida, Tampa, Florida 33620-5250, USA.
J Am Chem Soc. 2010 Sep 22;132(37):12796-9. doi: 10.1021/ja1056246.
[Co(P1)], the cobalt(II) complex of the D(2)-symmetric chiral porphyrin 3,5-Di(t)Bu-ChenPhyrin, is an effective catalyst for catalyzing asymmetric olefin cyclopropanation with the acceptor/acceptor-type diazo reagent α-cyanodiazoacetates. The [Co(P1)]-catalyzed reaction is versatile and suitable for both aromatic and aliphatic olefins with varied electronic properties, including electron-rich and -poor olefins. The Co(II)-based catalytic system can be operated in a one-time protocol under mild conditions, affording the desired cyclopropane products in high yields with both high diastereo- and enantioselectivity. The resulting enantiomerically enriched 1,1-cyclopropanenitrile esters provide convenient access to a number of densely functionalized chiral cyclopropane derivatives, including α-cyclopropyl-β-amino acids.
[Co(P1)]，即 D(2)-对称手性卟啉 3,5-二(叔丁基)-ChenPhyrin 的钴(II)配合物，是一种有效的催化剂，可用于催化受主/受主型重氮试剂α-氰基二氮乙酸酯对不对称烯烃环丙烷化反应。[Co(P1)]催化的反应具有通用性，适用于具有不同电子性质的芳香族和脂肪族烯烃，包括富电子和缺电子烯烃。基于 Co(II)的催化体系可以在温和条件下一次性操作，以高收率和高非对映选择性和对映选择性获得所需的环丙烷产物。得到的对映体富集的 1,1-环丙烷腈酯为许多官能化的手性环丙烷衍生物，包括α-环丙基-β-氨基酸，提供了便利的途径。
