Novel C-organosilicon derivatives as leads for reverse-transcriptase-mediated anti-HIV-1 activity

Biomimetic polyorganosiloxanes: model compounds for new materials

“…is formed, with N-9 attachment of two bases at the termini of the two butyl chains. The CH 2 N NMR signals[42.2 ppm] are very similar to those in while data for the compound analogous to 18 but embodying two propyl, rather than butyl, chains prepared by others has NMR chemical shifts of 4.09, 45.7 ppm, respectively 13. Although the two halves of the molecule are indistinguishable in the1 CH 2 ) 4 Si(Me) 2 OSi(Me) 2 (CH 2 ) CH 2 ) 4 Si(Me) 2 OSi(Me) 2 (CH 2 CH 2 ) 4 Si(Me) 2 OSi(Me) 2 (CH 2 ) 4For both thymine and cytosine, two quite distinct products are formed in each case.…”

“…10%). The two products incorporating adenine (15,17) have clean NMR spectra suggesting only one region-isomer has been formed, and the 1 H/ 13 44 The lack of a single product in these cases is in contrast to the observed reactions using silyl-protected bases in these reactions, as discussed earlier.…”

“…However, as far as we are aware, there has only been very limited attention given to silicon-based materials functionalised by the nucleobases. Déléris et al carried out the most significant studies, with the aim of producing anti-HIV agents, 13 or improving the lipophilicity of oligodeoxynucleotides, 14,15 but none of these studies specifically addressed the formation of siloxane polymers. More recent work has focussed on the synthesis of nanostructured organosilica materials by hydrolysis of (EtO) 3 Si(CH 2 ) n -subsituted bases, 16 and the resulting solids were characterised by solid-state NMR.…”

“…Our own interest in silicon-based polymers, 21 and in particular polysiloxanes, 22,23 has led us to look more closely at the chemistry of the latter polymer backbones functionalised by nucleobases, which might ultimately afford novel, self-organising materials. While our synthetic methodology builds on the earlier work of Déléris, [13][14][15] our emphasis is on the synthesis and structural chemistry of both precursors and model compounds as well as the polymers themselves, with a view to understanding more fundamentally the nature of any selfassembly processes.…”

“…The structure of 4 showing the atom labelling scheme; ellipsoids are at the 60% level. Selected geometric data for the molecule based on Si(1) as representative: Si(1)-O(2) 1.6893(18), N(1)-C(4) 20 1.363(4), N(1)-C(8) 1.395(3), N(1)-C(3) 1.474(2), N(2)-C(7) 1.305(4), N(2)-C(8) 1.371(4), O(1)-C(8) 1.237(3), O(2)-C(7) 1.344(3), C(1)-C(2) 1.291(5), C(2)-C(3) 1.501(4), C(4)-C(5) 1.348(4), C(5)-C(7)1.418(4), C(5)-C(6) 1.503(4) Å; O(2)-Si(1)-C(10) 110.20(13), O(2)-Si(1)-C(9) 111.27(13), C(10)-Si(1)-C(9) 111.87(17), O(2)-Si(1)-C(11) 99.98(13), C(10)-Si(1)-C(11) 111.17(16), C(9)-Si(1)-C(11) 111.77(17), C(4)-N(1)-C(8) 121.4 (2), C(7)-N(2)-C(8) 118.7 (2), C(7)-O(2)-Si(1) 126.31(17), C(1)-C(2)-C(3) 123.0(3), N(1)-C(3)-C(2) 111.5(2), C(5)-C(4)-N(1) 121.4(2), C(4)-C(5)-C(7)114.6(2), N(2)-C(7)-C(5) 125.8 (2), N(2)-C(Hydrogen bond data: H(24)-O(1) 2.29, H(4'')-O(3) 2.34 Å, C(24)-H(24)-O(1) 158.8, C(4)-H(4)-O(3) 164.0 o . Symmetry operations: ' 3/2-x,1/2+y,z-1/2; '' 3/2-x,1/2-y,1/2+z.…”