Effects of Molecular Oxygen, Solvent, and Light on Iridium-Photoredox/Nickel Dual-Catalyzed Cross-Coupling Reactions
详细信息 查看全文
- 作者：Martins S. Oderinde ; Adrian Varela-Alvarez ; Brian Aquila ; Daniel W. Robbins ; Jeffrey W. Johannes
- 刊名：Journal of Organic Chemistry
- 出版年：2015
- 出版时间：August 7, 2015
- 年：2015
- 卷：80
- 期：15
- 页码：7642-7651
- 全文大小：491K
- ISSN：1520-6904
文摘
In order to achieve reproducibility during iridium-photoredox and nickel dual-catalyzed sp3鈥搒p2 carbon鈥揷arbon bond-forming reactions, we investigated the role that molecular oxygen (O2), solvent and light-source (CF lamp or blue LED) play in a variety of Ir-photoredox mediated transformations. The presence of O2 was discovered to be important for catalyst activation when air-stable Ni(II) precatalysts were used in DMF under CF lamp irradiation; however, O2 was not required for catalysis when conducted with Ni(COD)2 in the same reaction system. O2 is believed to promote rapid reduction of the Ni(II) precatalyst by Ir(II) to Ni(0). In addition to O2, the effects that solvent and light-source have on the dual-catalyzed decarboxylative cross-coupling reactions will be discussed. These findings have enabled us to develop a more robust dual-catalyzed decarboxylative cross-coupling protocol.