- Heteroaromatic thioether-organostannane cross-coupling.
-
[reaction: see text] Heteroaromatic thioethers and aryl, heteroaryl, and alkenylstannanes participate in a palladium-catalyzed, copper(I)-mediated cross-coupling reaction at 50 degrees C in THF.
- Egi, Masahiro,Liebeskind, Lanny S
-
-
Read Online
- Metal-halogen exchange using tri-n-butyl lithium magnesate in the diazine series: Diazine 49
-
We report herein the 'metal-halogen exchange' reaction in the diazine series with lithium tri-n-tributylmagnesate. The reaction was performed with 2-iodopyrazine, 2-methylsulfanyl-4-iodopyrimidine and 3-iodo-6-phenylpyridazine. Benzophenone, aldehydes and
- Buron, Frédéric,Plé, Nelly,Turck, Alain,Marsais, Francis
-
-
Read Online
- HFIP Promoted Low-Temperature SNAr of Chloroheteroarenes Using Thiols and Amines
-
A highly efficient and an unprecedented hexafluoro-2-propanol, promoting low-temperature aromatic nucleophilic substitutions of chloroheteroarenes, has been performed using thiols and (secondary) amines under base-free and metal-free conditions. The developed protocol also provides excellent regio-control for the selective functionalization of dichloroheteroarenes, while the utility of the protocol was demonstrated by the modification of a commercially available drug ceritinib.
- Bhujabal, Yuvraj B.,Vadagaonkar, Kamlesh S.,Gholap, Aniket,Sanghvi, Yogesh S.,Dandela, Rambabu,Kapdi, Anant R.
-
p. 15343 - 15354
(2019/12/04)
-
- Pd/PTABS: Low-Temperature Thioetherification of Chloro(hetero)arenes
-
The thioetherification of heteroaryl chlorides is an essential synthetic methodology that provides access to bioactive drugs and agrochemicals. Due to their (actual or potential) industrial importance, the development of efficient and low-temperature protocols for accessing these compounds is a requirement for economic and ecologic reasons. A particular highly effective catalytic protocol using the Pd/PTABS system at only 50 °C was developed accordingly. The coupling between chloroheteroarenes and a variety of less reactive arylthiols and alkylthiols was carried out with a high efficiency. Heteroarenes of commercial relevance such as purines and pyrimidines were also found to be useful substrates for the reported transformation. The commercial drug Imuran (azathioprine) was synthesized as an example, and its preparation could be optimized. DFT studies were performed to understand the electronic effects of the tested ligands on the catalytic reaction.
- Bandaru, Siva Sankar Murthy,Bhilare, Shatrughn,Cardozo, Jesvita,Chrysochos, Nicolas,Schulzke, Carola,Sanghvi, Yogesh S.,Gunturu, Krishna Chaitanya,Kapdi, Anant R.
-
p. 8921 - 8940
(2019/07/08)
-
- Palladium-catalyzed heteroaryl thioethers synthesis overcoming palladium dithiolate resting states inertness: Practical road to sulfones and NH-sulfoximines
-
We provide efficient synthetic access to heteroaryl sulfones in two-steps using a simple palladium–1,1′-bis[(diphenyl)phosphanyl]ferrocene catalyst to form in high yields variously functionalized heteroaromatic thioethers. Pyridinyl-containing substrates can be subsequently selectively oxidized into sulfones and NH-sulfoximines by using very mild oxidation conditions with a high functional group tolerance. In the palladium-catalyzed C–S coupling of heteroaromatic thiols, reactivity limitation is attached with electron-deficient thiols. We show that this limitation can be resolved by the successful use of 2-bromoheteroarenes in the C–S coupling. We established herein that this choice of heteroaryl electrophilic reagent in palladium-catalyzed C–S bond formation allows overcoming palladium dithiolate out-of-cycle resting state inertness. This was illustrated in the stoichiometric reactivity study of the palladium dithiolate formed from 4-trifluoromethylbenzen-1-thiol –isolated and characterized by multinuclear NMR and XRD– with both 2-chloropyridine and 2-bromopyridine.
- Guilbaud, Johan,Labonde, Marine,Selmi, Awatef,Kammoun, Majed,Cattey, Hélène,Pirio, Nadine,Roger, Julien,Hierso, Jean-Cyrille
-
-
- Thioetherification of Chloroheteroarenes: A Binuclear Catalyst Promotes Wide Scope and High Functional-Group Tolerance
-
A constrained binuclear palladium catalyst system affords selective thioetherification of a wide range of functionalized arenethiols with chloroheteroaromatic partners with the highest turnover numbers (TONs) reported to date and tolerates a large variety of reactive functions. The scope of this system includes the coupling of thiophenols with six- and five-membered 2-chloroheteroarenes (i.e., functionalized pyridine, pyrazine, quinoline, pyrimidine, furane, and thiazole) and 3-bromoheteroarenes (i.e., pyridine and furane). Electron-rich congested thiophenols and fluorinated thiophenols are also suitable partners. The coupling of unprotected amino-2-chloropyridines with thiophenol and the successful employment of synthetically valuable chlorothiophenols are described with the same catalyst system. DFT studies attribute the high performance of this binuclear palladium catalyst to the decreased stability of thiolate-containing resting states. Palladium loading was as low as 0.2 mol %, which is important for industrial application and is a step forward in solving catalyst activation/deactivation problems.
- Platon, Mélanie,Wijaya, Novi,Rampazzi, Vincent,Cui, Luchao,Rousselin, Yoann,Saeys, Mark,Hierso, Jean-Cyrille
-
p. 12584 - 12594
(2016/08/25)
-
- Copper-free sonogashira coupling reaction using a trans-spanning 1,2-Bis(2-thienylethynyl)benzene ligand
-
Novel copper-free Sonogashira coupling reaction of aryl halides with terminal acetylenes proceeded in the presence of 1,2-bis(2-thienylethynyl) benzene (1) as a trans-bidentatable ligand.
- Atobe, Shingo,Sonoda, Motohiro,Suzuki, Yuki,Shinohara, Hiroyuki,Yamamoto, Takuya,Ogawa, Akiya
-
supporting information; experimental part
p. 980 - 982
(2012/02/01)
-
- Efficient nucleophilic substitution reactions of pyrimidyl and pyrazyl halides with nucleophiles under focused microwave irradiation
-
Rapid nucleophilic displacement reactions of 2-chloropyrimidine, 2-bromopyrimidine, 5-bromopyrimidine and chloropyrazine with nucleophiles under microwave irradiation was complete within several minutes with yields up to 99%. The method using microwave irradiation is superior to the classical heating processes.
- Cherng, Yie-Jia
-
p. 887 - 890
(2007/10/03)
-
- Syntheses in the nitrogen π-deficient heterocycles series using a barbier type reaction under sonication. Diazines. Part 29
-
Barbier type reaction with lithium metal has been tested under sonication on pyridines, a cinnoline and on various diazines. This very convenient method allows a very fast and smooth functionalization of these heterocycles. (C) 2000 Elsevier Science Ltd.
- Leprêtre, Anne,Turck, Alain,Plé, Nelly,Quéguiner, Guy
-
p. 3709 - 3715
(2007/10/03)
-
- REACTIONS OF CYCLOHEXYL AND ARYL PYRAZINYL SULFOXIDES WITH TRIFLUOROACETIC ANHYDRIDE
-
Cyclohexyl pyrazinyl sulfoxides reacted with trifluoroacetic anhydride to give 1-cyclohexenyl pyrazinyl sulfides and/or cyclohexyl hydroxypyrazinyl sulfides.The presence of alkyl groups on the pyrazine ring is essential to obtain the latter compounds.
- Shimazaki, Makoto,Hikita, Miyuki,Hosoda, Tomoko,Ohta, Akihiro
-
p. 937 - 947
(2007/10/02)
-