Ke Yung King

Electronic and steric effects of various silyl groups in radical addition reactions

Abstract The ligands on a silicon atom in allylsilanes were found to influence the efficiency of their reaction with ketones in the presence of MnO 2 . An electron-donating group on silicon provided a promoting effect, yet the steric effect of a bulky silyl group retarded the addition process.

Design, Synthesis, and Binding Studies of Highly Water Soulble Nordihydroguaiaretic Acid Derivatives : a DNA Major Groove Binder

A water-soluble derivative of nordihydroguaiaretic acid (NDGA, 1) was synthesized by coupling NDGA with N, N-dimethylglycine in the presence of dicyclohexylcarbodiimide and dimethylaminopyridine in CH2Cl2.The coupled product was further treated with HCl (g) to form tetraglycinylated NDGA 4 . HCl(G4N, 2) with 87% yield. Use of the fluorescence and the UV techniques in combination provided the apparent binding constants of G4N with WTabDNA as 5.05 X 100000 M-1 and with C98ab DNA as 8.23 X 100000 M-1, and with CT DNA as 1.31 X 1000000 M-1. Under acidic conditions, G4N showed greater binding ability. Results from experiments and computations indicate that G4N could function as a DNA major groove binder.