Ruthenium-Catalyzed Chemo- and Enantioselective Hydrogenation of Isoquinoline Carbocycles
Ruthenium-Catalyzed Chemo- and Enantioselective Hydrogenation of Isoquinoline Carbocycles
复制标题
DOI：
10.1021/acs.joc.8b00190
复制
发表时间：
2018-04-06
影响因子：
3.6
通讯作者：
Kuwano, Ryoichi
中科院分区：
文献类型：
--
作者：
Jin, Yushu;Makida, Yusuke;Kuwano, Ryoichi
以Ru（methalallyl）（2）（cod）和反式螯合手性配体PhTRAP为催化剂，实现了异喹啉碳环的化学选择性加氢。在这种氢化中实现的独特的化学选择性可以归因于手性配体的反式螯合作用。催化剂的制备过程对碳环加氢反应的重现性有很大影响。对5-、6-、7-和8-取代异喹啉的碳环进行选择性氢化，得到5，6，7，8-四氢异喹啉，产率高，对映选择性中等或良好。一些机理研究表明，在5-取代异喹啉的氢化中，在芳环上的H-2的初始加成过程中产生了立体中心。换句话说，立体化学控制伴随着脱芳构化。
A chemoselective hydrogenation of isoquinoline carbocydes was achieved by using the catalyst prepared from Ru(methallyl)(2)(cod) and trans-chelate chiral ligand PhTRAP. The unique chemoselectivity achieved in this hydrogenation could be ascribed to the trans-chelation of the chiral ligand. The procedure for preparing the catalyst strongly affects the reproducibility of the carbocyde hydrogenation. Various 5-, 6-, 7-, and 8-substituted isoquinolines were selectively hydrogenated at their carbocycles to afford 5,6,7,8-tetrahydroisoquinolines as major products in high yields with moderate or good enantioselectivities. Some mechanistic studies suggested that the stereogenic center was created during the initial addition of H-2 to the aromatic ring in the hydrogenation of 5-substituted isoquinolines. In other words, the stereochemical control was accompanied by the dearomatization.