Regioselective Palladium-Catalyzed Arylation of 4-Chloropyrazoles
摘要:
A highly regioselective Pd-catalyzed arylation of N-methylpyrazoles with aryl bromides is described. This transformation was studied extensively via automated reaction screening. A Design of Experiments (DoE) approach for optimizing the critical parameters was applied, resulting in excellent conditions for preparing selectively 5-arylpyrazoles in moderate to excellent yields under mild conditions.
A porous polymeric ligand (PPL) has been synthesized and complexed with copper to generate a heterogeneous catalyst (Cu@PPL) that has facilitated the efficient C-N coupling with various (hetero)aryl chlorides under mild conditions of visible-light irradiation at 80 °C (58 examples, up to 99% yields). This method could be applied to both aqueous ammonia and substituted amines, and is compatible to a
Catalytic C–H Allylation and Benzylation of Pyrazoles
作者:Seri Bae、Ha-Lim Jang、Haeun Jung、Jung Min Joo
DOI:10.1021/jo5025317
日期:2015.1.2
general approach for the synthesis of allylated and benzylated pyrazoles. An electron-withdrawing substituent, such as nitro, chloro, and ester groups, at C4 renders the Lewis basic nitrogen atom to be less basic and the C–H bond more acidic than the ones of the parent ring, enabling Pd-catalyzed C–H allylation and benzylation reactions of pyrazoles. The new method expanding the scope of the C–H functionalization
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
Nickel Phosphite/Phosphine-Catalyzed C–S Cross-Coupling of Aryl Chlorides and Thiols
作者:Kieran D. Jones、Dennis J. Power、Donald Bierer、Kersten M. Gericke、Scott G. Stewart
DOI:10.1021/acs.orglett.7b03560
日期:2018.1.5
A method for the coupling of aryl chlorides and thiophenols using an air-stable nickel(0) catalyst is described. This thioetherification procedure can be effectively applied to a range of electronically diverse aryl/heteroaryl chlorides without more expensive metal catalysts such as palladium, iridium, or ruthenium. This investigation also illustrates both, a variety of thiol coupling partners and
描述了一种使用空气稳定的镍(0)催化剂偶联芳基氯化物和苯硫酚的方法。这种硫醚化方法可以有效地应用于多种电子形式的芳基/杂芳基氯化物,而无需使用更昂贵的金属催化剂,例如钯,铱或钌。该研究还说明了多种硫醇偶合配偶体,并且在某些情况下还说明了Cs 2 CO 3的使用。
Room-temperature borylation and one-pot two-step borylation/Suzuki–Miyaura cross-coupling reaction of aryl chlorides
作者:Hong Ji、Li-Yang Wu、Jiang-Hong Cai、Guo-Rong Li、Na-Na Gan、Zhao-Hua Wang
DOI:10.1039/c8ra01381k
日期:——
strategy of arylchlorides is described. Utilizing Buchwald's second-generation preformed catalyst, boronate esters were obtained for a wide range of substrates in high yield. The method was also applied to Suzuki–Miyaura cross-coupling reaction in a one-pot two-step sequential manner, providing a facile and convenient access to the direct synthesis of biaryl compounds from arylchlorides.