Kaige Shen, Tian Liang, Yihao Zhang, Xinyan Ke, Ni Shao-Fei, Pengfei Li, Lixing Zhao, Wenjun Li
Organocatalytic enantioselective construction of axially chiral tetrasubstituted allenes has been achieved from the reaction between α-(2-hydroxynaphthalen-8-yl)propargylic alcohols and 2-arylindoles for the first time. With the aid of a suitable chiral phosphoric acid, alkynyl 8-methylenenaphthalen-2(8 H )-one was formed in situ from the corresponding α-(2-hydroxynaphthalen-8-yl)propargylic alcohol, followed by enantioselective 1,8-conjugate addition of 2-arylindole to afford the target axially chiral tetrasubstituted allenes in 70–95% yields with 64–94% ee. Notably, this work establishes the 2-hydroxynaphthalen-8-yl unit as an effective auxiliary group that enables the corresponding α-functionalized propargylic alcohols for the construction of enantioenriched tetrasubstituted allenes, which enrich the chemistry of quinone methides.