N2h4-H2o Enabled Umpolung Cyclization Of O-Nitro Chalcones For The Construction Of Quinoline N-Oxides

Umpolung is a unique strategy which converts the property of an atom into the opposite one. An efficient and general method for the construction of quinoline N-oxides via umpolung of carbonyl groups was developed from ortho-nitro chalcones and hydrazine in basic conditions. The strategy is transition-metal free and has good functional group tolerance, environmental friendliness, as well as mild reaction conditions with nitrogen gas as the byproduct.