secondary alkylbromides with aryl and alkenyl triflates and nonaflates has been developed. This challenging reaction was enabled by the use of a very bulky imidazole‐based phosphine ligand, which resulted in good yields as well as good chemo‐ and site selectivities for a broad range of substrates at room temperature and under non‐aqueous conditions. This reaction was extended to primary alkyl bromides
Palladium-Catalyzed Conversion of Aryl and Vinyl Triflates to Bromides and Chlorides
作者:Xiaoqiang Shen、Alan M. Hyde、Stephen L. Buchwald
DOI:10.1021/ja107481a
日期:2010.10.13
The palladium-catalyzed conversion of aryl and vinyltriflates to aryl and vinyl halides (bromides and chlorides) has been developed using dialkylbiaryl phosphine ligands. A variety of aryl, heteroaryl, and vinyl halides can be prepared via this method in good to excellent yields.
A Fluorinated Ligand Enables Room-Temperature and Regioselective Pd-Catalyzed Fluorination of Aryl Triflates and Bromides
作者:Aaron C. Sather、Hong Geun Lee、Valentina Y. De La Rosa、Yang Yang、Peter Müller、Stephen L. Buchwald
DOI:10.1021/jacs.5b09308
日期:2015.10.21
A new biaryl monophosphine ligand (AlPhos, L1) allows for the room-temperature Pd-catalyzed fluorination of a variety of activated (hetero)aryl trifiates. Furthermore, aryl triflates and bromides that are prone to give mixtures of regioisomeric aryl fluorides with Pd-catalysis can now be converted to the desired aryl fluorides with high regioselectivity. Analysis of the solid-state structures of several Pd(II) complexes, as well as density functional theory (DFT) calculations, shed light on the origin of the enhanced reactivity observed with L1.