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. 2020 Apr 1;142(13):5974-5979.
doi: 10.1021/jacs.0c01332. Epub 2020 Mar 20.

Enantioselective Hydroamination of Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer

Casey B Roos  1 , Joachim Demaerel  1 , David E Graff  1 , Robert R Knowles  1
Affiliations

Enantioselective Hydroamination of Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer

Casey B Roos et al. J Am Chem Soc. .

Abstract

An enantioselective, radical-based method for the intramolecular hydroamination of alkenes with sulfonamides is reported. These reactions are proposed to proceed via N-centered radicals formed by proton-coupled electron transfer (PCET) activation of sulfonamide N-H bonds. Noncovalent interactions between the neutral sulfonamidyl radical and a chiral phosphoric acid generated in the PCET event are hypothesized to serve as the basis for asymmetric induction in a subsequent C-N bond forming step, achieving selectivities of up to 98:2 er. These results offer further support for the ability of noncovalent interactions to enforce stereoselectivity in reactions of transient and highly reactive open-shell intermediates.

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Figures

Figure 1.
Figure 1.
(a) Examples of PCET-enabled enantioselective reactions; (b) Hypothesis for PCET-enabled asymmetric olefin hydroamination. (c) Enantioselective hydroamination with sulfonamides
Figure 2.
Figure 2.
Carboamination Reaction
See this image and copyright information in PMC

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