An efficient access to β-ketosulfones via β-sulfonylvinylamines: metal-organic framework catalysis for the direct C-S coupling of sodium sulfinates with oxime acetates.

Tuong A To,Hai H T Nguyen,Ngoc T H Nguyen,Anh T Nguyen,Nam T S Phan,Chau B Tran,Anh N Q Phan

doi:10.1039/c8ra02389a

Tuong A To, Hai H T Nguyen + Show 5 more

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https://doi.org/10.1039/c8ra02389a

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Abstract

A copper-based framework Cu2(OBA)2(BPY) was synthesized and used as a recyclable heterogeneous catalyst for the synthesis of β-sulfonylvinylamines from sodium sulfinates and oxime acetates via direct C–S coupling reaction. The transformation was remarkably affected by the solvent, and chlorobenzene emerged as the best option. This Cu-MOF displayed higher activity than numerous conventional homogeneous and MOF-based catalysts. The catalyst was reutilized many times in the synthesis of β-sulfonylvinylamines without considerably deteriorating in catalytic efficiency. These β-sulfonylvinylamines were readily converted to the corresponding β-ketosulfones via a hydrolysis step with aqueous HCl solution. To the best of our knowledge, this direct C–S coupling reaction to achieve β-sulfonylvinylamines was not previously conducted with a heterogeneous catalyst.

Highlights

Sulfone derivatives have emerged as essential intermediates for the synthesis of numerous compounds with potentially valuable biological activities.[1,2,3,4] Diverse synthetic protocols have been developed for the construction of these skeletons owing to their signi cance
The Cu-Metal–organic frameworks (MOFs) was initially used as a heterogeneous catalyst for the direct C–S coupling reaction between 1-(thiophen-2-yl)ethanone O-acetyl oxime and sodium benzenesul nate to produce (Z)-2(phenylsulfonyl)-1-(thiophen-2-yl)ethenamine (Scheme 1a)
No additional (Z)-2(phenylsulfonyl)-1-(thiophen-2-yl)ethenamine was detected. This result veri ed that the direct C–S coupling reaction utilizing Cu2(OBA)2(BPY) catalyst progressed under truly heterogeneous catalysis (Fig. 8)

Summary

Introduction

Sulfone derivatives have emerged as essential intermediates for the synthesis of numerous compounds with potentially valuable biological activities.[1,2,3,4] Diverse synthetic protocols have been developed for the construction of these skeletons owing to their signi cance. Metal–organic frameworks (MOFs) are crystalline and selforganizing reticular materials, consisting of metal cations sharing polytopic organic linkers.[11,12,13,14,15] Applications of MOFs in the eld of catalysis are somewhat delaying behind other domains.[16,17] With remarkably high porosity and almost in nite synthetic tunability, MOFs have exhibited several advantages in catalysis over non-porous and zeolitic materials.[18,19] Generally, catalytically active sites on MOFs could originate from the metal-based building units or from functional groups on the organic linkers.[20,21,22] The isolation of metal points in the networks would provide a greater number of active sites for the reactants.[23,24] Many organic reactions conducted with MOFsbased catalysts have been declared in the literature.[20,25,26,27,28] b-sulfonylvinylamines and b-ketosulfones were not previously synthesized utilizing heterogeneous catalysts, and the exploration of recyclable catalysts should be necessary for the construction of these skeletons In this manuscript, we would like to illustrate an efficient access to b-sulfonylvinylamines from sodium sul nates and oxime acetates via direct C–S coupling reaction utilizing Cu2(OBA)2(BPY) metal–organic framework catalysis. These b-sulfonylvinylamines were readily converted to b-ketosulfones with a hydrolysis step with aqueous HCl solution

Experimental

Catalytic studies

Results and discussion

Conclusions