چكيده به لاتين
Recently, the synthesis of spirocyclopropyl compounds that are widely used as a basic unit in a number of natural products is important because of their diverse applications in the field of medicine, pharmacy and agriculture, as well as their use as precursors to synthesis many natural and synthetic materials. several synthesis methods have been reported for these compounds. In this work, the mechanism of synthesis of trans-2,3-dihydro-spiro[2-aroyl-3-aryl-cyclopropane]1,2-indene-1,3-diones was investigated which has already been done experimentally. Computations were performed with Gaussian 09 software, and quantum mechanical computational density method (DFT) at B3LYP level. This is a stereoselective reaction catalyzed by the LPSF nonmagnetic organocatalyst. First, all reactants structures, intermediates, products, and various catalyst configurations were optimized, then transition states were calculated. This reaction consists of three reactants (phenacyl bromide, 1,3-indanedione and benzaldehyde) which, during the three main levels, provide the desired intermediates for the production of product /products. There are two possible cis and trans paths to perform the reaction in the third level. By calculating the energy of the components participating in the reaction and investigating the energy diagrams, the activation energies for the first step of the cis and trans path are 33.14 Kcal/mole and 26.07 Kcal/mol, respectively, and for the second step 15.52 Kcal/mol and Kcal/mol is 12.34 which indicates that the trans path is more desirable and the reaction is stereoselective.
