Catalytic Asymmetric [3+2] Cycloadditions of C-3 Unsubstituted 2-Indolylmethanols: Regio-, Diastereo- and Enantioselective Construction of the Cyclopenta[b]indole Framework

• Published in: Advanced synthesis & catalysis Vol. 358; no. 23; pp. 3797 - 3808
• Main Authors: Zhu, Zi-Qi, Shen, Yang, Sun, Xiao-Xue, Tao, Ji-Yu, Liu, Jin-Xi, Shi, Feng
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 07.12.2016
• Subjects: [3+2] cycloaddition; asymmetric organocatalysis; Asymmetry; Catalysis; Catalysts; Construction; Cycloaddition; enantioselectivity; indolylmethanols; Phosphoric acid; Strategy; Transformations; vinylindoles
• ISSN: 1615-4150; 1615-4169
• DOI: 10.1002/adsc.201600931

The first catalytic asymmetric [3+2] cycloaddition of 2‐indolylmethanols with 3‐vinylindoles has been established, which makes use of C‐3 unsubstituted 2‐indolylmethanol as a C3 building block in the presence of a chiral phosphoric acid. By using this strategy, biologically important cyclopenta[b]indole frameworks were efficiently constructed with regiospecificity in high yields (up to 99%), excellent diastereo‐ and enantioselectivities (up to >95:5 dr, 96:4 er). This reaction not only represents the first catalytic asymmetric [3+2] cycloaddition of C‐3 unsubstituted 2‐indolylmethanols, but also has confronted the great challenges in 2‐indolylmethanol‐involved enantioselective transformations.