Pyridinium Ylide Assisted Highly Stereoselective One-Pot Synthesis of trans-2-(4-Chlorobenzoyl)-3-aryl-spiro[cyclopropane-1,2′-inden]-1′,3′-diones and Their Antimicrobial and Nematicidal Activities

A series of highly stereoselective polysubstituted cyclopropane derivatives were synthesized via one-pot two-step tandem reaction starting from pyridine, 4-chloro phenacyl bromide, 1,3-indandione and aromatic aldehydes in acetonitrile using triethylamine as catalyst. Pyridinium ylide generated from 4-chloro phenacyl bromide undergo cyclopropanation with 2-arylidene-2H-indene-1,3-dione in situ afford the title compounds. Structures of all the compounds were confirmed by their analytical and spectral studies. Single crystal X-ray analysis was also performed on compound 4c in order to determine the crystal structure. All the compounds were screened for antimicrobial and nematicidal activities. Significant antimicrobial activity was shown by the compounds derived from 2-hydroxybenzaldehyde (4i) and 4-(dimethylamino)benzaldehyde (4m) against all the tested bacterial and fungal strains. Compound 4i has shown good activity (48% mortality) against Meloidogyne incognita after 48h of exposure at 250 mu g/mL concentration.