Authors:	Eckhardt, Paul Elliot, Quintin Alabugin, Igor V. Opatz, Till
Title:	Two paths to oxidative C−H amination under basic conditions : a theoretical case study reveals hidden opportunities provided by electron upconversion
Online publication date:	30-Jan-2023
Year of first publication:	2022
Language:	english
Abstract:	Traditionally, cross-dehydrogenative coupling (CDC) leads to C−N bond formation under basic and oxidative conditions and is proposed to proceed via a two-electron bond formation mediated by carbenium ions. However, the formation of such high-energy intermediates is only possible in the presence of strong oxidants, which may lead to undesired side reactions and poor functional group tolerance. In this work we explore if oxidation under basic conditions allows the formation of three-electron bonds (resulting in “upconverted” highly-reducing radical-anions). The benefit of this “upconversion” process is in the ability to use milder oxidants (e. g., O2) and to avoid high-energy intermediates. Comparison of the two- and three-electron pathways using quantum mechanical calculations reveals that not only does the absence of a strong oxidant shut down two-electron pathways in favor of a three-electron path but, paradoxically, weaker oxidants react faster with the upconverted reductants by avoiding the inverted Marcus region for electron transfer.
DDC:	540 Chemie 540 Chemistry and allied sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 09 Chemie, Pharmazie u. Geowissensch.
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-8700
Version:	Published version
Publication type:	Zeitschriftenaufsatz
License:	CC BY-NC-ND
Information on rights of use:	https://creativecommons.org/licenses/by-nc-nd/4.0/
Journal:	Chemistry - a European journal 28 60
Pages or article number:	e202201637
Publisher:	Wiley-VCH
Publisher place:	Weinheim
Issue date:	2022
ISSN:	1521-3765
Publisher DOI:	10.1002/chem.202201637
Appears in collections:	DFG-491381577-H