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Figure 1. DNA-encoded solid-phase synthesis. (A) TentaGel Rink-amide resin (160-μm diameter) is first elaborated with a common linker (gray) containing a coumarin chromophore and arginine. Linker resin is further functionalized with an alkyne and Fmoc-protected glycine. Azide-functionalized DNA headpiece (HDNA), consisting of two complementary strands of DNA (cyan) covalently joined via two PEG tethers (magenta), is coupled substoichiometrically (0.004 equiv) to alkyne sites via CuAAC, yielding bifunctional-HDNA resin (Fmoc-protected amine for chemical coupling and 5′-phosphoryl-CC-3′ overhang for enzymatic cohesive end ligation). (B) A forward primer module (green) is first enzymatically ligated to resin. Encoded synthesis proceeds as alternating steps of monomer coupling (scaffold elements shown in purple hues, side chain elements shown in orange hues) and coding module ligation (correspondingly in purple or orange hues). After the last encoding step, a reverse primer module (green) is ligated. The finished resin displays oligomer and a structure-encoding DNA message flanked by primer binding sequences for PCR amplification. (C) The DNA sequence encodes the series of reaction conditions that the bead experienced. Here, the DNA sequence encodes acylation with chloroacetic acid, treatment with methylamine, acylation with (2,3)-5-chloro-2,4-dimethyl-3-pentenoic acid, treatment with 3-methoxypropylamine, and acylation with -Fmoc--proline followed by Fmoc removal.
Synthesis And Characterization Of Oligomers
With respect to indoleoligomers of relevance to eumelanin, we are now in a position to incorporatehomocoupling as a final step in our iterative syntheses, shown schematically inFigure 2.
This is the focus of current efforts. Another recent development in the labhas been the purchase of a CEM Explorer 12 Hybrid microwave synthesizer(purchased with start-up funds). We are beginning to investigate the potential benefits of microwavereactions for the homocoupling reaction and other palladium-catalyzed reactionsuseful for the construction of indole oligomers.
Synthesis And Characterization Of Oligomers - …
The oligomers are composed of four to eight monomers and are heterogeneous in nature. Such oligomers are within the range of modern organic synthesis, similar to oligoarene foldamers. The ability to produce well-defined synthetic oligomers will advance our knowledge of this common but poorly understood biomaterial. This grant focuses on developing the synthetic methods necessary to generate indole and dihydroxyindole oligomers of relevance to eumelanin.
Synthesis of Arylenevinylene Oligomers by Heck Reaction.
Oligomers are the low-molecular-weight members of polymeric compounds in the molecular weight range from a few hundred to several thousand. Because of their unique physical properties, clearly differing from those of conventional low-molecular-weight compounds and high polymers, oligomers are currently used in many practical fields. This review summarizes methods for oligomer synthesis, primarily by addition oligomerization, and ralated reactions.
The scope of this review encompasses (i) the principle and examples of the synthesis of “telechelic” oligomers with a functional group at both chain-ends by addition (radical, cationic, anionic, and group-transfer) oligomerizations ; and the preparation of telechelic oligomers with ethynyl terminals and linear phenol-formaldehyde oligomers; (ii) the synthesis of “macromers” (oligomers having a polymerizable end-group) by ionic and radical mechanisms and their polymerization reactivity ; and (iii) the synthesis of cyclic or cyclic unit-containing oligomers. Problems in these oligomer syntheses are also discussed briefly.
Chemical synthesis of DNA oligomers containing …
B., Synthesis of azide-alkyne fragments for click' chemical applications; formation of oligomers from orthogonally protected trialkylsilyl-propargyl azides and propargyl alcohols.