99329-34-7Relevant academic research and scientific papers
Synthesis of zwitterionic palladium complexes and their application as catalysts in cross-coupling reactions of aryl, heteroaryl and benzyl bromides with organoboron reagents in neat water
Ramakrishna,Dastagiri Reddy
, p. 8598 - 8610 (2017/07/12)
N-(3-Chloro-2-quinoxalinyl)-N′-arylimidazolium salts (aryl = 2,6-diisopropylphenyl [HL1Cl]Cl, aryl = mesityl [HL2Cl]Cl) have been synthesized by treating 2,3-dichloroquinoxaline with the corresponding N′-arylimidazole in neat water. Facile reactions of these imidazolium salts with Pd(PPh3)4 and Pd2(dba)3/PPh3 (dba = dibenzyledene acetone) at 50 °C have afforded zwitterionic palladium(ii) complexes [Pd(HL1)(PPh3)Cl2] (I) and [Pd(HL2)(PPh3)Cl2] (II) in excellent yields. I and II have been tested for their ability to catalyze Suzuki-Miyaura cross coupling (SMC) reactions in neat water/K2CO3 and are found to be highly active for carrying out these reactions between aryl bromides and organoboron reagents. Furthermore, the scope of the catalyst I was also examined by employing (hetero)aryl bromides, hydrophilic aryl bromides, benzyl bromides and various organoboron reagents. More than 80 aryl/benzyl bromide-arylboronic acid combinations were screened in neat water/K2CO3 and it was found that I was a versatile catalyst, which produced biaryls/diarylmethanes in excellent yields. A TON of 82 000 was achieved by using I. Studies on the mechanism have also been carried out to investigate the involvement of carbene complexes in the catalytic path. Poison tests and a two-phase test were also conducted and the results are reported.
A Zwitterionic Palladium(II) Complex as a Precatalyst for Neat-Water-Mediated Cross-Coupling Reactions of Heteroaryl, Benzyl, and Aryl Acid Chlorides with Organoboron Reagents
Ramakrishna, Visannagari,Rani, Morla Jhansi,Reddy, Nareddula Dastagiri
, p. 7238 - 7255 (2018/01/01)
The Suzuki–Miyaura cross-coupling (SMC) reactions of several heteroaryl chlorides, benzyl chlorides, and aryl acid chlorides with (hetero)arylboron reagents have been investigated in the presence of [Pd(HL1)(PPh3)Cl2] (I) [HL1 = 3-[(2,6-diisopropylphenyl)-1-imidazolio]-2-quinoxalinide] as catalyst and K2CO3 as base in neat water. The synthesis of the heterocycle-containing biaryls required the addition of 2 mol-% of a phosphine ligand (PPh3 or X-Phos). A combination of more than 115 substrates were screened and it was found that I is a versatile catalyst that can produce heterocycle-containing biaryls, diarylmethanes, and benzophenones in moderate-to-excellent yields.
Palladium-catalyzed synthesis of heterocycle-containing diarylmethanes through suzuki-miyaura cross-coupling
Kuriyama, Masami,Shinozawa, Mina,Hamaguchi, Norihisa,Matsuo, Seira,Onomura, Osamu
, p. 5921 - 5928 (2014/07/08)
The heterocycle-containing diarylmethane synthesis from chloromethyl(hetero)arenes with (hetero)arylboron reagents was attained using the palladium/ether-imidazolium chloride system. This coupling process tolerated a diverse range of heteroaromatic moieties with sufficient catalytic activity to achieve the efficient synthesis of various diheteroarylmethanes in good to excellent yields.
Solvent Effects on Isomer Distributions and Relative Rates in Friedel-Crafts Benzylation and Benzoylation of Dibenzofuran Derivatives
Keumi, Takashi,Nakamura, Masatoshi,Kitamura, Masao,Tomioka, Naoto,Kitajima, Hidehiko
, p. 909 - 914 (2007/10/02)
The positional reactivity order in Friedel-Crafts benzoylation and benzylation of dibenzofuran (DBF) is found to be 2 > 3 > 1 >= 4.Both the partial rate factors and the positional selectivity for the benzylation of DBF are very low compared with those of
