Mechanistic Insights and Implications of Dearomative Rearrangement in Copper-Free Sonogashira Cross-Coupling Catalyzed by Pd-Cy*Phine

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• 作者：Adrian M. Mak ; Yee Hwee Lim ; Howard Jong ; Yong Yang ; Charles W. Johannes ; Edward G. Robins ; Michael B. Sullivan
• 刊名：Organometallics
• 出版年：2016
• 出版时间：April 11, 2016
• 年：2016
• 卷：35
• 期：7
• 页码：1036-1045
• 全文大小：674K
• 年卷期：0
• ISSN：1520-6041

文摘

The reaction mechanism for the in situ prepared Pd-Cy*Phine catalyst used in copper-free Sonogashira coupling was investigated using density functional theory. In addition, the significance of the meta-terarylphosphine ligand architecture of Cy*Phine was probed, as it had been previously shown experimentally to augment catalytic activity relative to its biarylphosphine analogue, XPhos. The calculated reaction barriers and free energies for the steps in the catalytic cycle suggest that the suppression of a dearomative rearrangement pathway is likely to be an important feature for the improved catalytic performance observed for the Pd-Cy*Phine system.