Synthesis of a Solid-Phase Amino Imidazotriazine Library via Palladium Catalyzed Direct Arylation

The crystal structure of (4SR)-7-(3,4-dichlorobenzyl)-4,8,8-trimethyl-7,8-dihydroimidazo[5,1c][1,2,4]triazine-3,6(2H,4H)-dione, C15H16Cl2N4O2

C15H16Cl2N4O2, monoclinic, P21/c (no. 14), a = 26.2014(7) Å, b = 7.59320(10) Å, c = 17.9766(4) Å, β = 109.217(3)°, V = 3377.20(14) Å3, Z = 8, R gt (F) = 0.0503, wR ref (F 2) = 0.1411, T = 100.0(1) K.

Recent Developments in Solid-Phase Strategies towards Synthetic, Sequence-Defined Macromolecules

Sequence-control in synthetic polymers is an important contemporary research area because it provides the opportunity to create completely novel materials for structure-function studies. This is especially relevant for biomimetic polymers, bioactive and information security materials. The level of control is strongly dependent and inherent upon the polymerization technique utilized. Today, the most established method yielding monodispersity and monomer sequence-definition is solid-phase synthesis. This Focus Review highlights recent advances in solid-phase strategies to access synthetic, sequence-defined macromolecules. Alternatives strategies towards sequence-defined macromolecules are also briefly summarized.

The twinned crystal structure of (4SR)-7-benzyl-2,4,8,8-tetramethyl-7,8-dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione, C16H20N4O2

C16H20N4O2, triclinic, P1̅ (no. 2), a = 9.0959(5) Å, b = 9.1993(5) Å, c = 18.5825(9) Å, α = 100.534(4)°, β = 94.120(4)°, γ = 94.752(4)°, V = 1517.44(13) Å3, Z = 4, Rgt(F) = 0.0801, wRref(F2) = 0.2371, T = 100(1) K.

Synthesis of many different types of organic small molecules using one automated process

Small-molecule synthesis usually relies on procedures that are highly customized for each target. A broadly applicable automated process could greatly increase the accessibility of this class of compounds to enable investigations of their practical potential. Here we report the synthesis of 14 distinct classes of small molecules using the same fully automated process. This was achieved by strategically expanding the scope of a building block-based synthesis platform to include even C(sp3)-rich polycyclic natural product frameworks and discovering a catch-and-release chromatographic purification protocol applicable to all of the corresponding intermediates. With thousands of compatible building blocks already commercially available, many small molecules are now accessible with this platform. More broadly, these findings illuminate an actionable roadmap to a more general and automated approach for small-molecule synthesis.

Regioselective synthesis of 7,8-dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives: A new drug-like heterocyclic scaffold

Dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives were prepared by successive N3- and N1-alkylation of hydantoins, followed by regioselective thionation and subsequent cyclization under mild conditions. In a final alkylation step a further substituent may be introduced. The synthetic strategy allows broad structural variation of this new drug-like heterobicyclic scaffold. In addition to extensive NMR and MS analyses, the structure of one derivative was confirmed by X-ray crystallography.

Direct C-H arylation of purine on solid phase and its use for chemical libraries synthesis

C(8)-H direct arylation of purine derivatives immobilized on Wang resin is described. The purine skeleton was immobilized via C(6)-regioselective substitution of 2,6-dichloropurine with polymer-supported amines. After N(9)-alkylation with two different alkyl iodides and C(2) substitution with two selected amines, reaction conditions for C(8)-H arylation were developed and optimized. Various aryl bromides and aryl iodides were used for the reaction affording the target 2,6,8,9-tetrasubstituted purines in very good purity. The same reaction conditions were also applied for the synthesis of 2,6,8-trisubstituted purines, however, yields were lower. The methodology is applicable for high throughput synthesis of chemical libraries comprised of purine scaffold.