An efficient method for the facile synthesis of (E)-monoarylidene derivatives of homo- and heterocyclic ketones with various aldehydes in the presence of a pyrrolidine organocatalyst has been achieved. A range of α,β-unsaturated ketones were obtained in moderate to high yields (up to 99%). Unlike the Claisen-Schmidt condensation process, the formation of undesired bisarylidene byproducts is not observed. The possible reaction mechanism suggests that the reaction proceeds via a Mannich-elimination sequence.
high yield synthesis of monoarylidene derivatives of cyclic systems directly from the reaction of ketone with various aldehydes under solvent-free conditions. Reactions took place rapidly in the presence of catalytic amounts of pyrrolidine, while no significant formation of the undesired bis by-products was observed. Moreover, the procedure was applicable to both homo- and heterocyclicketones.
Green synthesis of dissymmetric bisarylidene derivatives of cyclohexanone analogues under ultrasonic conditions
作者:Mohammad M. Mojtahedi、Leila Afshinpoor、Fatemeh Karimi、M. Saeed Abaee
DOI:10.1007/s13738-018-1498-5
日期:2019.2
AbstractA new procedure is developed for the synthesis of dissymmetric bisarylidene derivatives of two cyclohexanone analogues. Under mild ultrasonic/organocatalytic conditions, the first aldehyde reacts with the ketone to give the monoarylidene intermediate which subsequently condenses with the second aldehyde upon addition of NaOH/MeOH to the reaction mixture. Both condensations proceed in one pot