Enantioselective Friedel–Crafts Alkylation Reaction of Heteroarenes with N-Unprotected Trifluoromethyl Ketimines by Means of Chiral Phosphoric Acid |
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Authors: | Dr Masamichi Miyagawa Masaru Yoshida Yuki Kiyota Prof Dr Takahiko Akiyama |
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Institution: | Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo, 171-8588 Japan |
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Abstract: | An enantioselective Friedel–Crafts alkylation reaction of pyrroles and indoles with N-unprotected trifluoromethyl ketimines by use of chiral phosphoric acid provided α-trifluoromethylated primary amines bearing chiral tetrasubstituted carbon centers in high yields and with high to excellent enantioselectivities. The present reaction is unique to N-unprotected trifluoromethyl ketimines. No reaction took place with N-p-methoxyphenyl (PMP)-substituted ketimine. Corresponding α-trifluoromethylated amines were transformed without loss of enantioselectivity. |
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Keywords: | chiral phosphoric acid indoles nucleophilic addition pyrroles trifluoromethyl ketimine |
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