Background: Designing efficient methods for the synthesis of complex molecules with predefined
functionalities is a challenging task in modern organic chemistry. In this context, multicomponent
reactions (MCRs), by virtue of their applications, constitute a central academic and industrial
investigation domain. Recently, MCRs involving vinylogous Michael addition have attracted increasing
interest as one of the most useful key reactions for the synthesis of poly substituted benzene derivatives
such as spiro[cyclohexanes-1,3’-indoline]-2’,3-diones, spiroacenaphthylene, benzo[α]cyclooctenes,
etc. Therefore, development of an efficient method for a MCR which encompass vinylogous Michael
addition as vital reaction is of current interest.
Methods: We explored catalytic efficiency of DABCO in the multi-component reaction of cyclic ketone,
aldehyde and two moles of malononitrile for the synthesis of functionalized condensed bicyclic
compounds viz tetrahydroindenes, tetrahydronaphthalenes, hexahydrobenzo annulenes and hexahydrobenzo[
Results: The reaction conditions were optimized by screening of catalyst and solvent. Employing optimized
reaction conditions library of bicyclic compounds viz. tetrahydroindenes, tetrahydronaphthalenes,
hexahydrobenzoannulenes and hexahydrobenzoannulenes were synthesized in short time duration.
The synthesized products were characterized by 1H, 13C, IR and MS. Spectral data obtained was
in good agreement with the structure of products.
Conclusion: We disclosed DABCO catalyzed multi-component reaction of aldehyde, cyclic ketone and
malononitrile furnished corresponding tetrahydronaphthalenes, tetrahydroindalenes, hexahydrobenzo
annulenes and hexahydrobenzoannulenes, with a high level of complexity. Notably, this methodology
provides a facile access to various multi-functional compounds. The operational simplicity and
good yields, combined with step and atom-economic aspects, clean reactions yielded pure products,
hence no requirement of tedious chromatographic purification makes this synthetic strategy highly attractive
and promising approach from sustainable and practical chemistry.