碱催化2-硝基查尔酮和β-酮酯绿色高效构筑咔唑类衍生物OACSTPCD

Under base-promoted and transition-metal-free conditions,2-nitrochalcone and β-keto ester compounds serve as raw materials to selectively form four bonds via intramolecular conjugate addition and activation of the nitro group.This approach culminates in a one-pot,green,and efficient synthesis of 13 carbazole deriva-tives with yields ranging from 75%to 90%.Firstly,the enolization intermediate was obtained by Michael addition,and then reacted with nitro groups to form bicyclic intermediate.Under the induction of alkali,one molecule of hy-drogen peroxide is removed,converting to the targetcarbazole compound.This method has the advantages of simple and accessible raw materials,green and high efficiency,simple operation,high atomic economy,environmental friendliness,good yield and simple post-treatment,which provides a new strategy for synthesizing carbazole deriv-atives.