Executive Summary : | The current proposal intends to develop an array of triple, quadruple and quintuple cascade reactions using 2-arylidene-1,3-indanedione as a potential precursor for the preparation of spirodecalins, bis spirocycles, and fused heterocycles. It is proposed that diverse spirocarbocycles and fused heterocyclic scaffolds such as indeno-pyrano-chromenones, indeno-thiochromenones, indeno-quinolinones, indolyl-indenes which are unexplored to date can be synthesized in one pot. This one-pot cascade process involves various reactions i.e. Knoevenagel condensation (KC), Freidel-Crafts Reaction (FC), Hetero Diels-Alder (HDA), Hemi-ketalization (HK), Aldol, Nitro-Michael, Michael (conjugate) additions using the above readily accessible precursor. The key point of the proposal is to carry out asymmetric organocatalysis which would impart chiral induction to access potential spirocyclic molecules with multiple stereogenic centers in their optically active forms. It is also proposed to use various aldehydes, ketones, β-nitrostyrene/ β-nitrostyrene derived adducts, α,β-unsaturated aldehyde derivatives as electrophilic partners to that can react with the 2-arylidene-1,3-indanediones. The reactions would offer various spirodecalins, bis-spirocycles, and fused heterocycles derivatives containing multiple stereocenters depending on the use of the reaction partners. Besides, there appears to have significant synthetic utility by using these methods that would afford potential chiral compounds in one-step. This proposal offers to develop a new set of cascade transformations and the proposed products have great value in terms of medicinal chemistry research. |