1. Synthesis of (3,6-dihydro-2H-pyran-2-yl)phosphonate derivatives and investigation of catalyst effect on frontier molecular orbitals using DFT method
- Author
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Gül Altınbaş Özpınar, Said Nadeem, Md. Shakhawoat Hossain, Sidika Polat Cakir, and Ayhan S. Demir
- Subjects
010405 organic chemistry ,Chemistry ,Organic Chemistry ,Diethyl ester ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Phosphonate ,0104 chemical sciences ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Pyran ,Organic chemistry ,Molecular orbital - Abstract
Hetero Diels-Alder (HDA) reactions between 2,3-dimethyl-1,3-butadiene and diethyl ester of aroyl phosphonates catalyzed by AlCl3 to afford (3,6-dihydro-2H-pyran-2-yl) phosphonate derivatives were investigated. Aroyl phosphonates with electron-withdrawing groups generally resulted in better isolated chemical yields. A stoichiometric amount of AlCl3 rather than a catalytic amount was necessary to activate the cycloaddition reaction. The amount of AlCl3 catalyst and its effect on LUMO of ethyl ester benzoyl phosphonate were also investigated by performing density functional theory (DFT) (B97D/6-31+G(d,p)) computations in dichloromethane. An increased loading of AlCl3 induced a considerable decrease in the LUMO energy of ethyl ester of benzoyl phosphonate. The computed Gibbs free activation energy is 17.03 kcal/mol in DCM at 0°C using the same computational level.
- Published
- 2016
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