An electron-deficient diene as ligand for palladium-catalyzed cross-coupling reactions: An efficient alkylation of aryl iodides by primary and secondary alkylzinc reagents

作者：Liu Qiang; Duan Hui; Luo Xiancai; Tang Yang; Li Gang; Huang Rong; Lei Aiwen^*

来源：Advanced Synthesis & Catalysis, 2008, 350(9): 1349-1354.

DOI：10.1002/adsc.200800118

• alkylation
• alkylzinc reagents
• C-C coupling
• diene ligand
• palladium

An electron-deficient diene, L(1), was found to be an effective ligand in facilitating palladium-catalyzed Negishi couplings involving primary and secondary alkylzinc reagents. The reactions took place readily at 60 degrees C in THF with 5 mol% of a catalyst generated in situ from bis(acetonitrile)palladium dichloride [PdCl(2)(MeCN)(2)] and L(1), and functional groups such as chloro, bromo, etc. attached to phenyl ring as well as beta-H atoms adjacent to the reaction site were well tolerated. The problematic isomerizations in secondary alkyzinc reagents involved in the reactions reported in the literature were also observed in our system when isopropylzinc chloride was employed alone as the nucleophile. However, the isomerization was significantly suppressed when i-Pr(2)Zn was utilized in the presence of L(1).

• 出版日期2008-6
• 单位武汉大学