Thorpe-Ingold Effect in Branch-Selective Alkylation of Unactivated Aryl Fluorides.
Presented herein is a general protocol for the alkylation of simple aryl fluorides with unbiased secondary Grignard reagents by means of nickel catalysis. This study revealed a general Thorpe-Ingold effect in the ligand backbone which confers a high degree of selectivity for the secondary carbon center in the C-C coupling event. This protocol is characterized by mild reaction conditions, robustness, and simplicity. Both electron-rich and electron-deficient aryl fluorides are suitable candidates in this transformation. Equally amenable are a variety of heterocycles, permitting the coupling without over alkylation at the electrophilic sites.
["O'Neill|Matthew J|MJ|", 'Riesebeck|Tim|T|', 'Cornella|Josep|J|http://orcid.org/0000-0003-4152-7098']
nickel heterocycles C−F activation cross-coupling isomerization