An efficient direct benzylic C-H amination via dehydrogenative-coupling by using an inexpensive catalyst/oxidant (CoBr2/(BuOOBu)-Bu-t-Bu-t) system is described. Various unmodified amides including primary or secondary sulfonamides, carboxamides, and carbamates preformed well with benzylic hydrocarbons with moderate to good yields. (C) 2011 Elsevier Ltd. All rights reserved.
DDQ-mediated direct oxidative coupling of amides with benzylic and allylic sp3 C–H bonds under metal-free conditions
A simple and efficient method for the direct oxidative coupling of amides with benzylic and allylic sp(3) C-H bonds using DDQ as an oxidant is described. A range of amides including benzamide, benzyl carbamate, and substituted sulfonamides reacted efficiently with various benzylic and allylic substrates under metal free conditions to afford amidation products in good to excellent yields. (C) 2012 Elsevier Ltd. All rights reserved.