Sterically Demanding Oxidative Amidation of α-Substituted Malononitriles with Amines Using O2.
An efficient amidation method between readily available 1,1-dicyanoalkanes and either chiral or nonchiral amines was realized simply with molecular oxygen and a carbonate base. This oxidative protocol can be applied to both sterically and electronically challenging substrates in a highly chemoselective, practical, and rapid manner. The use of cyclopropyl and thioether substrates support the radical formation of α-peroxy malononitrile species, which can cyclize to dioxiranes that can monooxygenate malononitrile α-carbanions to afford activated acyl cyanides capable of reacting with amine nucleophiles.
Department of Chemistry, Graduate School of Science, Tohoku University, Aza Aramaki, Aoba-ku, Sendai, 980-8578, Japan.
Jing
J
Li
School of Chemistry, University of Lincoln, Brayford Pool, Lincoln, LN6 7TS, UK. mlear@lincoln.ac.uk.
Martin J
0000-0003-2556-2029
MJ
Lear
Department of Chemistry, Graduate School of Science, Tohoku University, Aza Aramaki, Aoba-ku, Sendai, 980-8578, Japan. yhayashi@m.tohoku.ac.jp.
Yujiro
Y
Hayashi
amides; amines; peroxides; radicals; reaction mechanisms