1404074-47-0Relevant academic research and scientific papers
Pd-N-heterocyclic carbene complex catalysed C-H bond activation of 2-isobutylthiazole at the C5 position with aryl bromides
Khan, Siraj,Bu?day, Nesrin,Ya?ar, Sedat,Ullah, Naseem,?zdemir, ?smail
, p. 6281 - 6292 (2021)
An effective and efficient catalytic system has been reported for the synthesis of C5-arylated 2-isobutylthiazoles. Pd-N-heterocyclic carbene complexes like [Pd(μ-Cl)Cl(SIPr)]2(2) and (LCl2Pd-SIPr) (3:L= PPh3,4:L= Py;5:L= 3-CHO-Py) were synthesized and characterized by1H,13C,31P NMR, LC-MS/MS, elemental analysis, and FTIR spectroscopy. These Pd-N-heterocyclic carbene complexes were assessed for the first time as catalysts for the C-H arylation reaction of 2-isobutylthiazole at the C5 position with different (hetero)aryl bromides. The catalytic system showed a low catalyst loading (1 mol%) and did not require the use of additional additives such as pivalic acid. The catalytic system developed with these catalysts enables the synthesis of fine chemicals in high yields under aerobic or anaerobic conditions. All complexes showed moderate to good yields in the C5 direct arylation of 2-isobutylthiazole, while complex2exhibited higher catalytic activity than the other complexes.
C[sbnd]H Bond activation of 2-isobutylthiazole at C5 position catalysed by Pd-N-heterocyclic carbene complexes
Bu?day, Nesrin,Khan, Siraj,Ya?ar, Sedat,?zdemir, ?smail
, (2021/02/27)
A highly efficient and effective protocol has been developed for the synthesis of C5-(hetero)arylated 2-isobutylthiazole derivatives. Four different palladium N-heterocyclic carbene (Pd-NHCs) complexes [Pd(μ-Cl)Cl(SIMes)]2 (2), (LCl2Pd-SIMes) (3: L = PPh3; 4: L = Py; 5: L = 3-CHO-Py) were synthesized and used for the first time as a catalysts in direct C-H arylation reaction of 2-isobutylthiazole at C5 position. Utilizations of these catalytic systems, the arylation of 2-isobutylthiazole with substituted (hetero)aryl bromides efficiently proceeded at low catalyst loading (1mol%) and without any additives such as PivOH under argon or aerobic conditions at 120 °C in a short time. Different substituted (hetero)aryl bromides, even some deactivated or highly sterically hindered (hetero)arylbromides, with a wide range of functional groups were successfully utilized under the optimum reaction conditions. In all cases, the C5 arylated 2-isobutylthiazoles were obtained in moderate to excellent yields.
Solvent-free palladium-catalyzed direct arylation of heteroaromatics with aryl bromides
Bensaid, Souhila,Doucet, Henri
experimental part, p. 1559 - 1567 (2012/10/08)
Solvent is one of the major sources of waste in the course of catalyzed direct arylations. Some palladium-catalyzed direct arylations of heteroaromatics can be advantageously performed without any solvent. In the presence of palladium catalysts (1 mol%) and potassium acetate as the base, the direct 5-arylation of some thiazoles, thiophenes, furans, or pyrroles with aryl bromides as coupling partners proceeds highly regioselectively and in moderate to high yields. However, the use of these solvent-free conditions is limited to electron-deficient aryl bromides. Copyright
