Reaction of donor-acceptor cyclopropanes with 1,3-diphenylisobenzofuran. Lewis acid effect on the reaction pathway
作者:A. O. Chagarovskiy、O. A. Ivanova、E. M. Budynina、E. L. Kolychev、M. S. Nechaev、I. V. Trushkov、M. Ya. Mel’nikov
DOI:10.1007/s11172-013-0349-x
日期:2013.11
Sn(OTf)2, SnCl2, ZnCl2, GaCl3, and MgI2, proceeds as a formal [3+4]-cycloaddition leading to a newly formed seven-membered ring. This reaction was found to be typical of cyclopropane-1,1-diesters and dinitriles, as well as 1-nitrocyclo-propanecarboxylates containing aromatic, heteroaromatic, and vinylic substituents at the C(2) atom of the small ring. When Me3SiOTf, TiCl4, SnCl4, or BF3·OEt2 were used as initiators
在镧系元素三氟甲磺酸盐以及 CuOTf、Sn(OTf)2、SnCl2、ZnCl2、GaCl3 和 MgI2 存在下,供体-受体环丙烷与 1,3-二苯基异苯并呋喃的反应以正式的 [3+4]-环加成形式进行导致新形成的七元环。发现该反应是典型的环丙烷-1,1-二酯和二腈,以及在小环的 C(2) 原子上含有芳族、杂芳族和乙烯基取代基的 1-硝基环丙烷羧酸酯。当 Me3SiOTf、TiCl4、SnCl4 或 BF3·OEt2 用作引发剂时,通过环丙烷和亲核试剂与二烯部分的共轭 1,4-加成形成了不寻常的环状半缩醛。