Department of Chemistry, University of Texas at Austin , 1 University Station A5300, Austin, Texas, 78712, United States.
Org Lett. 2014 Mar 21;16(6):1708-11. doi: 10.1021/ol500368p. Epub 2014 Mar 5.
A collective synthesis of 8,14-dihydronorsalutaridine, 8,14-dihydrosalutaridine, norisosinomenine, and isosinomenine is reported. The strategy provides direct access to the correct oxidation level of the products. The combination of an organocatalyst guanidine superbase, a tertiary amine base, and a dehydrating agent was necessary for the successful Henry-Michael-dehydration cascade to form the phenanthrene motif. The required selective aliphatic nitro reduction could only be achieved under heterogeneous transfer-hydrogenation conditions.
报告了 8,14-二氢去甲血根碱、8,14-二氢血根碱、去甲异紫堇灵碱和异紫堇灵碱的集体合成。该策略为获得正确氧化水平的产物提供了直接途径。为了成功进行 Henry-Michael-脱水级联反应形成菲环母核，需要有机催化剂胍超强碱、叔胺碱和脱水剂的组合。只有在非均相转移氢化条件下才能实现所需的选择性脂肪族硝基还原。
