A Bulky Biaryl Phosphine Ligand Allows for Palladium-Catalyzed Amidation of Five-Membered Heterocycles as Electrophiles
作者:Mingjuan Su、Stephen L. Buchwald
DOI:10.1002/anie.201201244
日期:2012.5.7
The first palladium‐catalyzed amidation of five‐membered heterocyclic bromides with multiple heteroatoms was achieved using the Pd/1 catalyst system. N‐Arylated imidazoles, pyrazoles, thiazoles, pyrroles, and thiophenes were synthesized in moderate to excellent yield. Experimental results and DFT calculations point to the need for an electron‐rich and sterically demanding biaryl phosphine ligand to
令人难以置信的体积:使用 Pd/ 1催化剂体系实现了具有多个杂原子的五元杂环溴化物的首次钯催化酰胺化。N-芳基化咪唑、吡唑、噻唑、吡咯和噻吩以中等至优异的产率合成。实验结果和 DFT 计算表明需要富含电子且空间要求高的联芳膦配体来促进这些困难的反应。