Development of Titanium Dioxide-Supported Pd Catalysts for Ligand-Free Suzuki-Miyaura Coupling of Aryl Chlorides

被引：18

作者：

Yamada, Tsuyoshi ^{[1
]}

Masuda, Hayato ^{[1
]}

Park, Kwihwan ^{[1
]}

Tachikawa, Takumu ^{[1
]}

Ito, Naoya ^{[1
]}

Ichikawa, Tomohiro ^{[1
]}

Yoshimura, Masatoshi ^{[2
]}

Takagi, Yukio ^{[2
]}

Sawama, Yoshinari ^{[1
]}

Ohya, Yutaka ^{[3
]}

Sajiki, Hironao ^{[1
]}

机构：

[1] Gifu Pharmaceut Univ, Lab Organ Chem, 1-25-4 Daigaku Nishi, Gifu 5011196, Japan

[2] NE Chemcat Corp, Catalysts Dev Ctr, 678 Ipponmatsu, Numazu 4100314, Japan

[3] Gifu Univ, Dept Chem & Biomol Sci, 1-1 Yanagido, Gifu 5011193, Japan

来源：

CATALYSTS | 2019年 / 9卷 / 05期

基金：

日本学术振兴会;

关键词：

Suzuki-Miyaura reaction; palladium; heterogeneous catalyst; titanium oxide; anatase titania; aromatic chloride; HETEROGENEOUS PALLADIUM CATALYST; MESOPOROUS SILICA; HIGHLY EFFICIENT; NANOCOMPOSITE CATALYSTS; HYDROGEN GENERATION; BOND FORMATION; CARBON-CARBON; SOLVENT-FREE; NANOPARTICLES; REDUCTION;

D O I：

10.3390/catal9050461

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The catalyst activities of various heterogeneous palladium catalysts supported by anatase-, rutile- and brookite-type titanium oxide for ligand-free Suzuki-Miyaura cross-coupling reactions of aryl chlorides were evaluated. Palladium acetate [Pd(OAc)(2)], supported on anatase-type titanium oxide (TiO2) via acetonitrile solution impregnation process without reduction [Pd/TiO2 (anatase-type)], demonstrated the highest catalyst activity in comparison to those of other titanium oxide (rutile- or brookite-type) supported Pd(OAc)(2) without reduction and reduced Pd/TiO2 (anatase-type) [Pd(red)/TiO2 (anatase-type)]. Various aryl chloride and bromide derivatives were smoothly coupled with arylboronic acids including heteroarylboronic acids in the presence of 5-10 mol% Pd/TiO2 (anatase-type) without the addition of any ligands. Although the fresh Pd/TiO2 (anatase-type) catalyst was surprisingly comprised of ca. 1:2 mixture of palladium(II) and palladium(0) species according to X-ray photoelectron spectroscopy (XPS), in spite of no reduction process, significant further increment of palladium(0) species was observed during the Suzuki-Miyaura coupling reaction, and Pd/TiO2 (anatase-type) was converted into a catalyst, which contained palladium(0) species as the main component [ca. 1:5 mixture of palladium(II) and palladium(0) species]. Therefore, the reduction via the electron donation process to the palladium(II) species may have occurred during the reaction on anatase-type titanium oxide.

引用

页数：14

共 74 条

[31] Rationally designed palladium complexes on a bulky N-heterocyclic carbene-functionalized organosilica: an efficient solid catalyst for the Suzuki-Miyaura coupling of challenging aryl chlorides [J].