Aryl/heteroaryl pentafluorobenzenesulfonates (ArOPFBs): new electrophilic coupling partners for room temperature Suzuki–Miyaura cross-coupling reactions
摘要:
The first cross-coupling reaction between aryl/heteroaryl pentafluorobenzenesulfonates and aryl/heteroaryl boronic acids under mild conditions is described. The successful synthesis of highly ortho substituted biaryls and high chemoselectivity of these bench stable intermediates over tosylates, triflates, mesylates, and chlorides increases its scope as a valuable cross-coupling partner. The generality of this protocol was further extended to other boron containing nucleophiles (boronates, trifluoroborates) and alkyl boronic acids. (C) 2015 Elsevier Ltd. All rights reserved.
Pd-catalyzed C-H annulation reactions of halo- and aryl-heteroarenes were developed using readily available o-bromobiaryls and o-dibromoaryls, respectively. A variety of five-membered heteroarenes rapidly provided the corresponding phenanthrene-fused heteroarenes, which led to the identification of phenanthro-pyrazole and thiazole as new, stable -2 V redox couples. The flexible syntheses and tunability
Rh(II)-Catalyzed Ring Expansion of Pyrazoles with Diazocarbonyl Compounds as a Method for the Preparation of 1,2-Dihydropyrimidines
作者:Alexander N. Koronatov、Nikolai V. Rostovskii、Alexander F. Khlebnikov、Mikhail S. Novikov
DOI:10.1021/acs.joc.8b01228
日期:2018.8.17
A high yield synthesis of 1,2-dihydropyrimidines by the Rh(II)-catalyzed reaction of diazocarbonyl compounds with 1,4-di- and 1,4,5-trisubstituted pyrazoles is reported. This reaction represents the first example of a carbenoid insertion into a N–N bond and provides a novel approach to 4-unsubstituted 1,2-dihydropyrimidines with a broad range of functional group tolerance. According to DFT calculations
Palladium-catalysed direct diarylations of pyrazoles with aryl bromides: a one step access to 4,5-diarylpyrazoles
作者:Abdelilah Takfaoui、Liqin Zhao、Rachid Touzani、Pierre H. Dixneuf、Henri Doucet
DOI:10.1016/j.tetlet.2014.01.079
日期:2014.3
The palladium-catalyseddirect arylation of pyrazoles with aryl halides, using PdCl(C3H5)(dppb)/KOAc catalyst, reveals a similar reactivity of C4 and C5 CH bonds of pyrazoles, whereas the C3 CH bond is almost unreactive, and gives access in one step to a variety of 4,5-diarylpyrazoles. This CH bond functionalisation reaction tolerates a variety of substituents on the aryl bromide such as nitro, cyano
使用PdCl(C 3 H 5)(dppb)/ KOAc催化剂,钯催化吡唑与芳基卤化物的直接芳基化反应显示出吡唑的C4和C5 C H键具有相似的反应性,而C3 C H键几乎不具有反应性,并一步一步即可获得各种4,5-二芳基吡唑类化合物。该C H键官能化反应容许芳基溴化物上的各种取代基,例如硝基,氰基,甲酰基,丙酰基,酯,氯,氟或三氟甲基。
Pd-Catalysed Direct 5-Arylation of 1-Methylpyrazole with Aryl Bromides
作者:Hamed Ammar、Henri Doucet、Anissa Beladhria、Kassem Beydoun、Ridha Salem
DOI:10.1055/s-0030-1260076
日期:2011.8
the base and DMAc as the solvent, promotes the 5-arylation in moderate to high selectivities and yields. A wide variety of aryl and heteroaryl bromide derivatives have been successfully employed. Their electronic and steric properties also have an influence on the regioselectivities and yields of the coupling products. Both electron-poor and electron-rich aryl bromides gave satisfactory results, although
Construction of Heterobiaryl Skeletons through Pd-Catalyzed Cross-Coupling of Nitroarenes and Heterocyclic Arylborononate Esters with a Sterically Demanding NHC Ligand
作者:Wei Chen、Wanzhi Chen、Miaochang Liu、Huayue Wu
DOI:10.1021/acs.orglett.2c02796
日期:2022.9.30
cross-couplings of nitroarenes and heteroarylboronate esters has been developed. A number of heterobiaryl compounds containing pyridine, pyrimidine, quinoline, furan, thiophene, and pyrazole were prepared using [Pd(cinnamyl)Cl]2/2-aryl-5-(2,4,6-triisopropylphenyl)-2,3-imidazolylidene[1,5-a]pyridines as the catalysts in good to excellent yields. The synthetic practicality of this approach is demonstrated through
已经开发了钯催化的硝基芳烃和杂芳基硼酸酯的 Suzuki-Miyaura 交叉偶联。使用[Pd(肉桂基)Cl] 2 /2-芳基-5-(2,4,6-三异丙基苯基)-2,3-制备了许多含有吡啶、嘧啶、喹啉、呋喃、噻吩和吡唑的杂二芳基化合物咪唑亚基[1,5- a ]吡啶作为催化剂,收率良好。这种方法的合成实用性通过类药物分子的合成得到证明。