N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation.
J Org Chem. 2012 Jul 20;77(14):5993-6006. doi: 10.1021/jo300720d. Epub 2012 Jul 5.
A new approach for the dimerization of donor-acceptor cyclopropanes (2-arylcyclopropane-1,1-dicarboxylates) under double-catalysis conditions by treatment with 20 mol % of GaCl(3) and dimethyl 3,5-dimethyl-1-pyrazoline-3,5-dicarboxylate as a specific organocatalyst has been found. Under these conditions, the starting compounds are regio- and stereospecifically converted into polysubstituted 2-oxabicyclo[3.3.0]octanes. Two new rings, one C-O bond, and two C-C bonds are formed in this process, and four stereocenters are thus created. The reaction mechanism was thoroughly studied by NMR spectroscopy, and a number of intermediates were detected.
已发现一种新方法，可在双催化条件下通过使用 20mol%的 GaCl(3)和二甲基 3,5-二甲基-1-吡唑啉-3,5-二羧酸酯作为特定的有机催化剂，使供体-受体环丙烷（2-芳基环丙烷-1,1-二羧酸酯）二聚。在这些条件下，起始化合物被区域和立体特异性地转化为多取代的 2-氧杂双环[3.3.0]辛烷。在此过程中形成了两个新环、一个 C-O 键和两个 C-C 键，因此创建了四个立体中心。通过 NMR 光谱对反应机理进行了深入研究，并检测到了一些中间体。
