螺烯及其衍生物在不对称催化中的应用

Applications of Helicenes and Their Derivatives in Asymmetric Catalysis

螺烯是一类由多个芳(杂)环邻位稠合而成的具有螺旋手性的π共轭分子.与其他类型手性催化剂相比,螺烯类催化剂的研究起步晚、发展慢,但是由于螺烯分子具有刚性强、热稳定性好、易于衍生化、手性空间独特等特点,近年来螺烯作为手性催化剂在不对称合成中的应用研究引起了人们越来越多的关注与兴趣.根据螺烯在不对称催化反应中承担的角色不同,从螺烯作为手性诱导试剂、手性配体与有机小分子催化剂三方面综述螺烯类催化剂在不对称催化合成中的应用研究进展.

Helicenes are a kind of π-conjugated helical compounds which are consisted of ortho-fused benzene or other aromatic rings. Compared to other kinds of chiral catalysts, studies on helicene-based catalysts with helical chirality showed late start and lagging development. However, since helicene molecules exhibit structural rigidity, thermal stability, easily functionalization, and excellent chiral environment for asymmetric catalysis by continuous elaborate curve in three-dimensional space, investigation on the synthesis of helicene-based chiral catalysts and their applications in asymmetric catalysis have attracted increasing interest in recent years. According to the different roles of the helicenes played in the asymmetric catalysis, the helicene-based catalysts can be classified into chiral inducers, helically chiral ligands and helical organocatalysts, and their applications in asymmetric catalysis will be focused on in this review, respectively.