Intermolecular Heck Coupling with Hindered Alkenes Directed by Potassium Carboxylates
作者:Tucker R. Huffman、Yebin Wu、Alexis Emmerich、Ryan A. Shenvi
DOI:10.1002/anie.201813233
日期:2019.2.18
Pd0 -catalyzed Mizoroki-Heck reactions traditionally exhibit poor reactivity with polysubstituted, unbiased alkenes. Intermolecular reactions with simple, all-carbon tetrasubstituted alkenes are unprecedented. Herein we report that pendant carboxylic acids, combined with bulky monophospine ligands on palladium, can direct the arylation of tri- and tetrasubstituted olefins. Quaternary carbons are established
传统上,Pd0催化的Mizoroki-Heck反应与多取代,无偏烯烃的反应性较差。与简单的全碳四取代烯烃的分子间反应是前所未有的。在本文中,我们报道侧链羧酸与钯上的庞大单膦配体结合,可以指导三和四取代烯烃的芳基化。在高Fsp3连接环连接处建立季碳,并且偶联后可以除去羧酸酯导向基团。羧酸根的方向性可防止新的,取代度较低的烯烃过度芳基化,而后者在随后的反应中可能会多样化。