| 1. |
- Kunz, Susanna, et al.
(författare)
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Derivatization of 2,1,3-Benzothiadiazole via Regioselective C–H Functionalization and Aryne Reactivity
- 2024
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 89:9, s. 6138-6148
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Tidskriftsartikel (refereegranskat)abstract
- Despite growing interest in 2,1,3-benzothiadiazole (BTD) as an integral component of many functional molecules, methods for the functionalization of its benzenoid ring have remained limited, and many even simply decorated BTDs have required de novo synthesis. We show that regioselective Ir-catalyzed C–H borylation allows access to versatile 5-boryl or 4,6-diboryl BTD building blocks, which undergo functionalization at the C4, C5, C6, and C7 positions. The optimization and regioselectivity of C–H borylation are discussed. A broad reaction scope is presented, encompassing ipso substitution at the C–B bond, the first examples of ortho-directed C–H functionalization of BTD, ring closing reactions to generate fused ring systems, as well as the generation and capture reactions of novel BTD-based heteroarynes. The regioselectivity of the latter is discussed with reference to the Aryne Distortion Model.
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| 2. |
- Ni, Shengjun, et al.
(författare)
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Mechanochemical Solvent-Free Catalytic C-H Methylation
- 2021
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Ingår i: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 60:12, s. 6660-6666
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Tidskriftsartikel (refereegranskat)abstract
- The mechanochemical, solvent-free, highly regioselective, rhodium-catalyzed C-H methylation of (hetero)arenes is reported. The reaction shows excellent functional-group compatibility and is demonstrated to work for the late-stage C-H methylation of biologically active compounds. The method requires no external heating and benefits from considerably shorter reaction times than previous solution-based C-H methylation protocols. Additionally, the mechanochemical approach is shown to enable the efficient synthesis of organometallic complexes that are difficult to generate conventionally.
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| 3. |
- Hribersek, Matic, 1992-, et al.
(författare)
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Solvent-free and ball mill-free catalytic C–H methylation
- 2023
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Ingår i: Green Chemistry. - : RSC Publishing. - 1463-9262 .- 1463-9270. ; 25:22, s. 9138-9145
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Tidskriftsartikel (refereegranskat)abstract
- An expedient, mechanochemical, operationally simple protocol is reported for the Rh-catalysed C–H methylation of (hetero)arenes under solvent-free conditions without the use of a ball mill. Reagent mixing and activation are delivered using simple pestle-and-mortar grinding and subsequent heating, providing access to the same sustainability benefits as ball milling without the need for specialised equipment. Calculated E-factors are identical to those of ball milling and 5–25 times lower than for solution based conditions. The C–H methylation displays complete regioselectivity and good functional group tolerance. Reaction mixture analyses using scanning electron microscopy and differential scanning calorimetry are described.
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| 4. |
- Ingner, Fredric, et al.
(författare)
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Mechanochemical synthesis of (hetero)aryl Au(i) complexes
- 2020
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Ingår i: Green Chemistry. - : ROYAL SOC CHEMISTRY. - 1463-9262 .- 1463-9270. ; 22:17, s. 5648-5655
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Tidskriftsartikel (refereegranskat)abstract
- Growing demand for sustainable chemical syntheses casts mechanochemistry in a new light as an environmentally benign alternative to traditional solvent-based methods. Given recent interest in Au(i) complexes for catalytic, materials, and medicinal applications, we developed a mechanochemical protocol to prepare (hetero)aryl Au(i) complexes under green conditions. The procedure reported here uses C-H or C-B activation to afford the corresponding Au(i) complexes in high yields. Our approach bypasses external heating, long reaction times and the use of toxic solvents. We demonstrate that mechanochemical C-H auration can be used on highly functionalised bioactive substrates. Mechanistic aspects of the C-H auration are discussed.
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| 5. |
- Ingner, Fredric, et al.
(författare)
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Mild and Efficient Synthesis of Diverse Organo-Au-I-L Complexes in Green Solvents
- 2020
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Ingår i: ChemSusChem. - : WILEY-V C H VERLAG GMBH. - 1864-5631 .- 1864-564X. ; 13:8, s. 2032-2037
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Tidskriftsartikel (refereegranskat)abstract
- An exceptionally mild and efficient method was developed for the preparation of (hetero)aryl-Au-I-L complexes using ethanol or water as the reaction medium at room temperature and Ar-B(triol)K boronates as the transmetalation partner. The reaction does not need an exogeneous base or other additives, and quantitative yields can be achieved through a simple filtration as the only required purification method, which obviates considerable waste associated with alternative workup methods. A broad reaction scope was demonstrated with respect to both the L and (hetero)aryl ligands on product Au complexes. Despite the polar reaction medium, large polycyclic aromatic hydrocarbon units can be incorporated on the Au complexes in very good to excellent yields. The approach was demonstrated for the chemoselective manipulation of orthogonally protected aryl boronates to afford a new class of N-heterocyclic carbene-Au-aryl complexes. A mechanistic rationale was proposed.
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