Department of Chemistry, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada.
Chemistry. 2012 Jan 16;18(3):804-7. doi: 10.1002/chem.201103284. Epub 2011 Dec 16.
This base is just right! A new base, potassium 2,2,5,7,8-pentamethylchroman-6-oxide, for Pd-catalysed amination has been rationally designed that has sufficient basicity to efficiently deprotonate the intermediate aryl palladium ammonium complex, leading to far better rates than obtained with carbonate, which is known to be very mild. At the same time, this new base possesses minimal nucleophilicity to mitigate the degradation of base-sensitive functional groups in the starting materials and products, such as is commonly seen with potassium or sodium tert-butoxide.
这个碱位恰到好处！我们合理设计了一种新的碱位，即钾 2,2,5,7,8-五甲基色满-6-氧化物，用于钯催化的氨化反应。该碱位具有足够的碱性，可有效去质子化中间体芳基钯铵配合物，从而使反应速率远远高于使用众所周知的温和的碳酸盐所获得的反应速率。同时，这种新碱位的亲核性非常低，可以减轻起始原料和产物中对碱敏感的官能团的降解，这在使用叔丁醇钾或叔丁醇钠时是很常见的。
