“Molecular Chameleons”. Design and Synthesis of a Second Series of Flexible Nucleosides

Abstract

The second series of flexible shape-modified nucleosides is introduced. The "fleximers" feature the purine ring systems split into their individual imidazole and pyrimidine components. This structural modification serves to introduce flexibility to the nucleoside while still retaining the elements essential for recognition. As a consequence, these structurally innovative nucleosides can more readily adapt to their environment and should find use as bioprobes for investigating enzyme-coenzyme binding sites as well as nucleic acid and protein interactions. Their design and synthesis is described.

A Three‐Way Switchable Process for Suzuki Cross‐Coupling, Hydrodehalogenation, or an Assisted Tandem Hydrodehalogenation and Suzuki Cross‐Coupling Sequence

“…DART-mass spectra were obtained using PEG as an internal standard with positive ionization mode with TOF mass analyzer. 1 H NMR spectra were recorded on an NMR spectrometer operating at 400 MHz. 13 C NMR spectra were recorded on an NMR spectrometer operating at 150 MHz.…”

“…Access to backbone-substituted imidazoles is highly desired due to the versatility of this structural motif within medicinal chemistry, [1] in natural product synthesis, [2] and as precursors for NHC ligands in transition metal-and organo-catalysis. [3] 4,5-Diarylimidazoles bearing various substituents on the C-2 position are targets themselves owing to their diverse biological activity.…”

Transition metals in organic synthesis: Highlights for the year 2005

“…(9)) [150]. A variety of heteroaryl boronic acid derivatives were used such as, haloimidazolyl [151], 2-and 3-thiophenyl [152] in a synthesis of rebeccamycin analogs [153], 3-pyridyl [154], 5-pyrimidyl [155], 1,4,5,6-tetrahydropyridyl [156], 2-indolyl [157] and 3-furyl [158]. A ferrocenyl boronic acid reagent was coupled with a 1-iodonaphthalene [17].…”

“…Palladium-catalyzed reactions of hexamethylditin with aryl halides and alkenyl triflates to give aryl and alkenyl tin reagents [155,581] were employed in the synthesis of heterocyclic core of GE 2270 [34], core of roseophilin [21], frondosin C ring system [582], phorboxazole A analogs [71] and functionalized azaindoles [583].…”

Hetero-expanded Purine Nucleosides. Design, Synthesis and Preliminary Biological Activity

“…A number of research groups [1][2][3][4][5] , including ours [6][7][8][9] , have designed and synthesized a number of varients of structurally unique unnatural nucleosides to study various aspects of nucleic acid structure and function. Each new foray into the expansion of the genetic alphabet allows for further investigation of just how absolute the requirements for base-pairing and stacking, helix stability and recognition by enzyme systems such as polymerases or other nucleosidemetabolizing enzymes involved in critical biological processes, really are.…”