Photoinduced Olefin Diamination with Alkylamines.

Sebastian Govaerts,Charlotte Hampton,Alessandro Ruffoni,Daniele Leonori,Laia Malet-Sanz,Lucrezia Angelini

doi:10.1002/anie.202005652

Sebastian Govaerts, Charlotte Hampton + Show 4 more

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https://doi.org/10.1002/anie.202005652

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Abstract

Vicinal diamines are ubiquitous materials in organic and medicinal chemistry. The direct coupling of olefins and amines would be an ideal approach to construct these motifs. However, alkene diamination remains a long‐standing challenge in organic synthesis, especially when using two different amine components. We report a general strategy for the direct and selective assembly of vicinal 1,2‐diamines using readily available olefin and amine building blocks. This mild and straightforward approach involves in situ formation and photoinduced activation of N‐chloroamines to give aminium radicals that enable efficient alkene aminochlorination. Owing to the ambiphilic nature of the β‐chloroamines produced, conversion into tetra‐alkyl aziridinium ions was possible, thus enabling diamination by regioselective ring‐opening with primary or secondary amines. This strategy streamlines the preparation of vicinal diamines from multistep sequences to a single chemical transformation.

Highlights

Vicinal diamines are important building blocks in organic chemistry with applications as commercial medicines and ligands in transition metal catalysis, as well as organocatalysts (Scheme 1A).[1]
We report a general strategy for the direct and selective assembly of vicinal 1,2-diamines using readily available olefin and amine building blocks. This mild and straightforward approach exploits the in situ formation and photoinduced activation of N-chloroamines leading to aminium radicals that enable efficient alkene aminochlorination
We recently questioned if this reactivity profile for amine activation could be exploited in order to enable intermolecular reaction of aminium radicals with alkenes leading to an olefin aminochlorination that would serve as stepping stone to achieve a general and direct strategy leading to olefin diamination

Summary

Introduction

Vicinal diamines are important building blocks in organic chemistry with applications as commercial medicines and ligands in transition metal catalysis, as well as organocatalysts (Scheme 1A).[1]. Supporting information for this article is given via a link at the end of the document While successful, these strategies do not enable the direct introduction of alkylamine substituents, which are a prominent class of nitrogenated motifs frequently found in the high-value materials mentioned above. The preparation of this class of substrates is still based on lengthy synthetic sequences, relying on functional group manipulation around epoxides,[11] a-Br-ketones[12], or ahydroxy-acids.[13] In this article, we report the development of a general process for the direct and selective construction of unsymmetrical diamines wherein readily available primary and secondary amines are sequentially added with complete siteselectivity across olefin building blocks. A) Relevance of vicinal diamines: examples of bioactive molecules and ligands [N] [N]

H R2N vs R2N via

Findings

Conclusions