Pd-Catalyzed Enantioselective Tandem C-C Bond Activation/Cacchi Reaction between Cyclobutanones and o-Ethynylanilines
Wan-Chun Yang1, Xiao-Bing Chen1, Kun-Long Song1
1Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, and Key Laboratory of Organosilicon Material Technology of Zhejiang Province, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou 311121, P.R. China.
Abstract:
A palladium-catalyzed asymmetric tandem C-C bond activation/Cacchi reaction between cyclobutanones and o-ethynylanilines was reported. The transient chiral σ-alkylpalladium species generated via enantioselective C(sp3)-C(sp2) bond activation of cyclobutanones promotes cyclization of o-ethynylanilines, leading to one-carbon-tethered chiral indanone-substituted indoles. Two C-C bonds and one C-N bond are created with concomitant formation of an all-carbon quaternary stereocenter. Furthermore, a chiral C2-aryl axis can be created in 2,3-disubstituted indole moiety, leading to indanone-substituted indoles with both central and axial stereogenic elements.
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