Ligand-Accelerated Iron Photocatalysis Enabling Decarboxylative Alkylation of Heteroarenes
摘要:
A mild, practical protocol for the decarboxylative alkylation of heteroarenes has been accomplished via iron photocatalysis. A diverse range of carboxylic acids readily undergo oxidative decarboxylation and then couple with a broad array of heteroarenes in this transformation. The photoexcited state lifetimes of iron complexes are typically much shorter than those of iridium and ruthenium complexes. Here we describe our effort on iron photocatalysis by utilizing the intramolecular charge transfer pathway of iron-carboxylate complexes.
Radical-Based Regioselective C–H Functionalization of Electron-Deficient Heteroarenes: Scope, Tunability, and Predictability
作者:Fionn O’Hara、Donna G. Blackmond、Phil S. Baran
DOI:10.1021/ja406223k
日期:2013.8.14
of substituents exert consistent and additive effects on the regioselectivity of substitution. This allowed us to establish guidelines for predicting regioselectivity on complex π-deficient heteroarenes, including pyridines, pyrimidines, pyridazines, and pyrazines. Since the relative contribution from opposing directing factors was dependent on solvent and pH, it was sometimes possible to tune the regiochemistry