Synthesis 2023; 55(21): 3644-3651
DOI: 10.1055/a-2088-4302
special topic
C–H Bond Functionalization of Heterocycles

Selective Deuteration of Heterocycle N-Oxides via Iridium-Catalysed Hydrogen Isotope Exchange

Philippa K. Owens
a   Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, UK
,
a   Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, UK
,
Sebastien Campos
b   Medicines Research Centre, GlaxoSmithKline R & D, Stevenage SG1 2NY, UK
,
a   Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, UK
,
a   Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, UK
› Institutsangaben
The authors thank the University of Strathclyde (B.I.P.S.; studentship), and GlaxoSmithKline and the EPSRC (P.K.O.; studentship EP/L505663/1) for funding.


Abstract

An iridium(I) N-heterocyclic carbene/phosphine complex has been applied to the C–H activation and hydrogen isotope exchange of quinoline N-oxides. The isotope labelling proceeds under exceptionally low catalyst loadings of 0.25 mol% and delivers products with high levels of deuterium incorporation selectively at the C8 position. A broad substrate scope is demonstrated, with the method tolerant of electron-poor and -rich substrates, and of substitution adjacent to the site of C–H activation. The isotope label is fully retained under standard deoxygenation conditions to give the corresponding labelled quinoline, and the labelling and deoxygenation can be combined in a one-pot procedure.

Supporting Information



Publikationsverlauf

Eingereicht: 01. März 2023

Angenommen nach Revision: 08. Mai 2023

Accepted Manuscript online:
08. Mai 2023

Artikel online veröffentlicht:
01. Juni 2023

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