State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Chemistry. 2021 Jan 7;27(2):735-739. doi: 10.1002/chem.202003647. Epub 2020 Dec 8.
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 a 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.
本工作报道了在手性有机碱催化下，邻醌甲醚（o-QMs）与α-硫氰酸基茚满酮之间的水触发的区域和对映选择性螺环化及级联反应。在螺环化反应中，痕量水的使用对于获得高对映选择性（高达 96%ee）至关重要。我们发现通过调节溶剂中水的比例可以实现级联反应。因此，开发了两种新的高效不对称反应，用于具有优异对映选择性（高达 99%ee）的螺和稠合茚满酮骨架的发散合成。机理研究表明，界面氢键可能在手性识别中发挥重要作用。
