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[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
Nickelaelectro-Catalyzed C─H Activation to β-Arylated Pyrroles via Multiple Dehydrogenation
Kazuhiro Okamoto1, Simon L Homölle1, Tristan von Münchow1
1Wöhler Research Institute for Sustainable Chemistry (WISCh), Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany.
Abstract:
Nickel electrocatalysis has emerged as a powerful strategy for sustainable C─H activation, offering an environmentally benign alternative to traditional methods based on stoichiometric oxidants. We, herein, report a nickela-electrocatalyzed approach for the expedient synthesis of β-arylated pyrroles via a unique multiple dehydrogenative C─H activation approach. Hence, direct C─C bond formation between pyrroles and arenes was enabled, obviating the need for prefunctionalized substrates. The reaction proceeded under electrochemical conditions in a user-friendly undivided cell, utilizing electricity as a traceless oxidant. Mechanistic studies, including cyclic voltammetry, provided support for a nickel(II/III/IV) regime, wherein anodic oxidation facilitates the dehydrogenation and C─H activation paired with the valuable hydrogen evolution reaction (HER). Our findings highlight the potential of electrocatalysis to unlock distinct reaction manifolds and provides a sustainable platform for accessing complex heteroaryl frameworks.
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