Otherwise Inert Reaction Of Sulfonamides/Carboxamides With Formamides Via Proton Transfer-enhanced Reacitvity

Weak intermolecular interaction including hydrogen and halogen bond, belong to the non-covalent bond, in essence, is the electrostatic interaction between the atoms. Plays an important role in the research areas of molecular recognition, functional materials, crystal engineering, supramolecular assembly, biological systems, and weak intermolecular interaction more and more attracted extensive attention from researchers, and gradually become a hot research field.This paper mainly discussed NBS-mediated addition-elimination reaction of sulfonamides/carboxamides and formamides afforded N-sulfonylamidines and N-formylarylamides, respectively, depending on different elimination fashion. This reaction is carried out under conditions of80℃. The products were characterized by1H NMR and13C NMR. Ami dine derivatives have been widely used in medicinal chemistry, as well as intermediates in organic synthesis. Through experimental and computational results show that the hydrogen bonding induced proton transfer is the key driving force for the reaction to take place. we subsequently introduce a halogen activator to do this reaction. The role of the halogen atom is to make TsNH2a stronger H-donor by the formation of TsBrN-H…O, and to derive a possible reaction mechanism. The protocol demonstrates the possibility of constructing chemical bond based on proton transfer strategy induced by noncovalent hydrogen bond interaction, which also provides an alternative method for building C-N chemical bonds.