Pd-PEPPSI-IPent: An Active, Sterically Demanding Cross-Coupling Catalyst and Its Application in the Synthesis of Tetra-Ortho-Substituted Biaryls
作者:Michael G. Organ、Selçuk Çalimsiz、Mahmoud Sayah、Ka Hou Hoi、Alan J. Lough
DOI:10.1002/anie.200805661
日期:2009.3.16
series of N‐heterocyclic carbene catalysts (see picture) were prepared and evaluated in the Suzuki–Miyaura reaction. A variety of sterically encumbered tetra‐ortho‐substituted biaryl products were formed from unreactive aryl chlorides using the isopentyl‐substituted catalyst at temperatures ranging from 65 °C to room temperature. The cyclopentyl‐substituted catalyst was virtually inactive, demonstrating
不可思议的体积:制备了一系列N杂环卡宾催化剂(参见图片),并在Suzuki-Miyaura反应中进行了评估。在65°C到室温的温度范围内,使用异戊基取代的催化剂,由未反应的芳基氯化物形成了多种空间受限的四邻位取代的联芳基产品。环戊基取代的催化剂几乎没有活性,这表明“柔性体积”对于促进这些转化至关重要。