24460-50-2Relevant academic research and scientific papers
Br?nsted Acid-Promoted Cyclodimerization of Indolyl Ketones: Construction of Indole Fused-Oxabicyclo[3.3.1]nonane and -Cyclooctatetraene Ring Systems
Zhao, Lang,Yan, Zhi-Hua,Tang, Shuai,Wei, Zhong-Lin,Liao, Wei-Wei
, p. 166 - 171 (2021/01/09)
A Br?nsted acid-promoted cyclodimerization of C(3)-, C(2)-, or N(1)-substituted indole ketone derivatives is described. A wide range of structurally diverse bisindole fused-9-oxabicyclo[3.3.1]nonane and bisindole fused-cyclooctatetraene (COT) derivatives can be prepared in good to high yields with high efficiency.
Remote enantioselective friedel-crafts alkylations of furans through HOMO activation
Li, Jun-Long,Yue, Cai-Zhen,Chen, Peng-Qiao,Xiao, You-Cai,Chen, Ying-Chun
, p. 5449 - 5452 (2014/06/09)
Catalytic asymmetric Friedel-Crafts alkylation is a powerful protocol for constructing a chiral C(sp2)-C(sp3) bond. Most previous examples rely on LUMO activation of the electrophiles using chiral catalysts with subsequent attack by electron-rich arenes. Presented herein is an alternative strategy in which the HOMO of the aromatic π system of 2-furfuryl ketones is raised through the formation of a formal trienamine species using a chiral primary amine. Exclusive regioselective alkylation at the 5-position occurred with alkylidenemalononitriles, and high reactivity and excellent enantioselectivity (up to 95 % ee) was obtained by this remote activation. Alternative strategy: An asymmetric and regioselective Friedel-Crafts alkylation reaction of 2-furfuryl ketones and alkylidenemalononitriles was developed and involves the in situ generation of a formal HOMO-raised trienamine species. A diversity of alkylation products were produced in moderate to excellent enantioselectivity under the catalysis of a chiral bifunctional primary amine-thiourea (1).
