| 1. |
|
|
| 2. |
- Odell, Luke R., et al.
(författare)
-
Synthesis of Substituted Indazole Acetic Acids by N-N Bond Forming Reactions
- 2023
-
Ingår i: European Journal of Organic Chemistry. - : Wiley-Blackwell. - 1434-193X .- 1099-0690. ; 26:29
-
Tidskriftsartikel (refereegranskat)abstract
- Herein, we report on the discovery and development of novel cascade N-N bond forming reactions for the synthesis of rare indazole acetic acid scaffolds. This approach allows for convenient synthesis of three distinct indazole acetic acid derivatives (unsubstituted, hydroxy, and alkoxy) by heating 3-amino-3-(2-nitroaryl)propanoic acids with an appropriate nucleophile/solvent under basic conditions. The reaction tolerates a range of functional groups and electronic effects and, in total, 23 novel indazole acetic acids were synthesized and characterized. This work offers a valuable strategy for the synthesis of useful scaffolds for drug discovery programs.
|
|
| 3. |
|
|
| 4. |
- Rydfjord, Jonas, et al.
(författare)
-
Route to 3-Amidino Indoles via Pd(II)-Catalyzed C-H Bond Activation
- 2017
-
Ingår i: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 19:15, s. 4066-4069
-
Tidskriftsartikel (refereegranskat)abstract
- We report a facile synthesis of 3-amidino indoles from indoles and cyanamides. The reaction is Pd(II)-catalyzed and proceeds via C-H bond activation of the indole in its 3-position followed by a 1,2-addition of the resulting indole-palladium σ-complex to a cyanamide, which provides the corresponding amidine. The preference for 4,5-diazafluoren-9-one (DAF) as the ligand is investigated using DFT calculations, and a plausible reaction pathway is presented.
|
|
| 5. |
- Schembri, Luke S, et al.
(författare)
-
A Base-Free, Low Temperature Click and Release Reaction for the In Situ Generation of Diazomethane
- 2023
-
Ingår i: Advanced Synthesis and Catalysis. - : Wiley-Blackwell. - 1615-4150 .- 1615-4169. ; 365:11, s. 1839-1845
-
Tidskriftsartikel (refereegranskat)abstract
- Diazomethane is a powerful reagent for numerous chemical reactions such as esterifications and the homologation of carboxylic acids. Unfortunately, the synthetic utility of diazomethane is severely limited by its toxicity and highly explosive nature. Diazald((R)) is typically used for ex situ synthesis, however it requires cumbersome and hazardous transfer of diazomethane from a caustic aqueous phase to the reaction medium. Herein, we present a low temperature and base-free insitu synthesis of diazomethane via a "click and release" reaction between an enamine and sulfonyl azide. Its utility is exemplified by the synthesis of diverse methyl esters in yields of up to 93%. Moreover, diazoketone synthesis from insitu generated diazomethane and acid chlorides was demonstrated for the first time. Finally, trideuteromethylation was achieved using acetone-d(6) as the deuterium source. We anticipate that this method will enable the safer use of diazomethane in organic synthesis and drug discovery programs.
|
|
| 6. |
- Skillinghaug, Bobo, 1986-, et al.
(författare)
-
Microwave Heated Continuous Flow Palladium(II)-Catalyzed Desulfitative Synthesis of Aryl Ketones
- 2016
-
Ingår i: Organic Process Research & Development. - : American Chemical Society (ACS). - 1083-6160 .- 1520-586X. ; 20:11, s. 2005-2011
-
Tidskriftsartikel (refereegranskat)abstract
- A protocol for Pd(II)-catalyzed desulfitative synthesis of aryl ketones from sodium aryl sulfinates and nitriles in continuous flow has been developed. The reactions proceed with microwave heating using microwave transparent tube reactors, affording the desired aryl ketones in fair to good yields. Microwave transparent aluminum oxide reactors were identified as a safe and thermostable alternative to borosilicate glass reactors.
|
|
| 7. |
- Skillinghaug, Bobo, 1986-
(författare)
-
Palladium(II)-Catalysed Heck and Addition Reactions : Exploring Decarboxylative and Desulfitative Processes
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Palladium complexes have the ability to catalyse cross-coupling of two organic moieties through the formation of transient metal-carbon bonds, thus bringing them closer to each other to facilitate the formation of a new bond. Palladium-catalysed coupling reactions are one of the most important carbon-carbon forming reactions available to organic chemists and many of these reactions rely on the reactivity of aryl-palladium complexes. The investigation of new aryl-palladium precursors is thus of great interest, especially as more sustainable and economic methods can be developed.This thesis describes the use of carboxylic acids and sodium arylsulfinates as such new arylating agents. Protocols for microwave-assisted palladium(II)-catalysed decarboxylative synthesis of electron-rich styrenes and 1,1-diarylethenes were developed. However, these transformations had very limited substrate scopes which prompted the investigation of sodium arylsulfinates as alternative arylating agents. These substrates were employed in the microwave-assisted palladium(II)-catalysed desulfitative addition to nitriles, and the substrate scope was demonstrated by combining a wide array of sodium arylsulfinates and nitriles to yield the corresponding aryl ketones. The application of the desulfitative reaction in a continuous flow setup was demonstrated, and aluminium oxide was identified as safe alternative to borosilicate glass as a reactor material. The mechanisms of the decarboxylative and desulfitative transformations were investigated by density functional theory (DFT) calculations. The desulfitative reaction was also investigated by direct electrospray ionization mass spectrometry (ESI-MS), providing further mechanistic insight. Finally, a protocol for the safe and convenient synthesis of a wide range of sodium arylsulfinates was developed.
|
|
| 8. |
|
|
| 9. |
- Skillinghaug, Bobo, et al.
(författare)
-
Palladium(II)-Catalyzed Desulfitative Synthesis of Aryl Ketones from Sodium Arylsulfinates and Nitriles : Scope, Limitations, and Mechanistic Studies
- 2014
-
Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 79:24, s. 12018-12032
-
Tidskriftsartikel (refereegranskat)abstract
- A fast and efficient protocol for the palladium(II)-catalyzed production of aryl ketones from sodium arylsulfinates and various organic nitriles under controlled microwave irradiation has been developed. The wide scope of the reaction has been demonstrated by combining 14 sodium arylsulfinates and 21 nitriles to give 55 examples of aryl ketones. One additional example illustrated that, through the choice of the nitrile reactant, benzofurans are also accessible. The reaction mechanism was investigated by electrospray ionization mass spectrometry and DFT calculations. The desulfitative synthesis of aryl ketones from nitriles was also compared to the corresponding transformation starting from benzoic acids. Comparison of the energy profiles indicates that the free energy requirement for decarboxylation of 2,6-dimethoxybenzoic acid and especially benzoic acid is higher than the corresponding desulfitative process for generating the key aryl palladium intermediate. The palladium(II) intermediates detected by ESI-MS and the DFT calculations provide a detailed understanding of the catalytic cycle.
|
|
| 10. |
|
|
