Catalytic effect of DABCO on C-C and C-N bond formation reactions

Abstract

Thesis Title: Catalytic effect of DABCO on C-C and C-N bond formation reactions

Carbon-carbon bond forming reaction is the most useful and fundamental reaction in organic synthesis. The Morita-Baylis-Hillman and Knoevenagel condensation reaction has been recognized as one of the versatile and economically feasible C-C bond forming rection to genenate multifunctional compounds. The formation of C-C and C-N bonds in modern organic synthesis is a key target for methodological advancement. Here a convenient method for the C-C bond formation reaction has been developed in good yield % in the presence of excellent base catalyst 1, 4-diazabicyclo [2. 2. 2] octane (DABCO) in THF at room temperature for 6 hrs. Firstly, a facile method for the synthesis of C-C bond formation compounds (3-6), (7-12) was developed from the reaction of 2-cyclohexenone/cyclohexanone with different arylaldehydes in the presence of DABCO at room temperature as shown in Scheme-1.

Scheme-1

Secondly, an expeditous method for the synthesis of C-C bond formation compounds (7-14) was developed from the reaction of N-substituded nitro-benzaldehyde (1-3) with different acrylales (4-6) in the presence of DABCO at room temperature as shown in the Scheme-2.

Scheme-2 Thirdly, the synthesis of C-C bond formation compounds (7-10) was developed from the reaction of diethylmalonate 1 with arylaldehydes (2-5) in the presence of DABCO at room temperature as shown in the Scheme-3.

2, 7 R = p-NO2; 3, 8 R= m-NO2; 4, 9 R = CHO; 5, 10 R = p-Cl;

Scheme-3

Finally, a convenient method for the synthesis of C-N bond formation compounds (10-15) was developed from the reaction of Tris (2-aminoethyl) amines 1 with different acrylates 2-7 in the presence of DABCO at room temperature as shown in the Scheme-4.

Scheme-4

All the synthesized compounds were characterized by analytical data obtained from IR, 1H NMR and 13C NMR spectra, elemental analysis and mass spectrophotometry to establish the structure. The SEM was taken for the analysis of surface morphology of the synthesized compounds 13, 14, 15, 16, 17 and TGA was taken for the compounds 16, 17.