Divergent Asymmetric Reactions of ortho-Quinone Methides with α-Thiocyanato Indanones for the Synthesis of Spiro- and Fused-indanones.
Divergent Asymmetric Reactions of ortho-Quinone Methides with α-Thiocyanato Indanones for the Synthesis of Spiro- and Fused-indanones.
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DOI：
10.1002/chem.202003647
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
Xianghui Liu;Kai Wang;Yan Liu;Can Li
中科院分区：
文献类型：
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作者：
Xianghui Liu;Kai Wang;Yan Liu;Can Li
报道了在手性有机碱的催化下，水引发邻苯二酚甲醚(o-QMS)与α-硫氰酸酯的化学发散对映选择性螺环和级联反应。在螺旋环的情况下，使用微量的水作为添加剂是实现高对映体选择性(高达96%ee)的关键。我们发现，只需调节溶剂中水的比例，就可以实现级联反应。因此，开发了两个新的高效的不对称反应，用于发散合成具有良好的对映体选择性(高达99%ee)的螺环和稠吲酮支架。机理研究表明，界面氢键可能在实现反应路径可切换方面起着重要作用。
Reported in this work is a water triggered chemo-divergent enantioselective spiro-annulation and cascade reaction of ortho -quinone methides ( o -QMs) with α-thiocyanato indanones catalyzed by a chiral organic base. In the case of spiro-annulation, the use of trace amount of water as additive is critical to achieve high enantioselectivity (up to 96% ee). We found that an cascade reaction was enabled by just tuning the ratio of water in solvent. Accordingly, two new highly efficient asymmetric reactions for the divergent synthesis of spiro- and fused-indanone scaffolds with excellent enantioselectivities (up to 99% ee) were developed. Mechanistic investigations suggest that interfacial hydrogen bonding may play an important role in achieving the switchable reaction pathways.