Ru(II)-Catalyzed C-H Activation: Amide-Directed 1,4-Addition of the Ortho C-H Bond to Maleimides.
Maleimide has been used as a selective coupling partner to generate conjugate addition products exclusively. The typical Heck-type oxidative coupling that occurs when alkenes are used is avoided by choosing maleimide as an alkene, which cannot undergo β-hydride elimination due to the unavailability of a syn-periplanar β-hydrogen atom. The amide nitrogen, which is notorious for undergoing tandem reactions to generate spirocyclic or annulation products under cross-coupling conditions, remains innocent in this report. Along with the substrate scope, a robustness screen has been performed to analyze the performance of amide as a directing group in the presence of other directing groups and also to examine the tolerance of the reaction conditions for other frequently encountered functional groups.
Department of Organic Chemistry, Indian Institute of Science , Bangalore, Karnataka 560 012, India.
Puspam
P
Keshri
Department of Organic Chemistry, Indian Institute of Science , Bangalore, Karnataka 560 012, India.
Kiran R
KR
Bettadapur
Department of Organic Chemistry, Indian Institute of Science , Bangalore, Karnataka 560 012, India.
Veeranjaneyulu
V
Lanke
Department of Organic Chemistry, Indian Institute of Science , Bangalore, Karnataka 560 012, India.
Kandikere Ramaiah
KR
Prabhu