Asymmetric Synthesis of 3,4-Diaminochroman-2-ones Promoted by Guanidine and Bisguanidium Salt
作者:Shunxi Dong、Xiaohua Liu、Yulong Zhang、Lili Lin、Xiaoming Feng
DOI:10.1021/ol2018888
日期:2011.10.7
A highly enantioselective synthesis of 3,4-diaminochroman-2-ones has been realized via the domino reaction of o-hydroxy aromatic aldimines and azlactones. Notably, a cis-product was obtained as the major product by the use of guanidine 2a whereas a trans-product was the major product with bisguanidium salt 3•HBArF4. In two cases, various substituted 3,4-dihydrocoumarins were obtained with high yields
通过邻羟基芳族醛亚胺和a内酯的多米诺反应,已经实现了对3,4-二氨基苯并二氢吡喃-2-酮的高度对映选择性的合成。值得注意的是,通过使用胍2a获得了顺式产物作为主要产物,而反式产物是双胍盐3•HBAr F 4的主要产物。在两种情况下,以高收率(高达99%),出色的对映选择性(高达99%ee)和非对映选择性(高达> 99:1顺式:反式和98:2 )获得了各种取代的3,4-二氢香豆素。反式:顺式,分别)在温和的反应条件下。