MSH Reagent

15 October, 2015 / by SK / in Reactions

4950

Overall Score3.5

Generality
Reagent Availability
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Criteria #4
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General Characteristics

MSH (O-(mesitylsulfonyl)hydroxylamine) is an electrophilic aminating agent used to introduce a NH₂ unit. It is used in reactions such as the Beckmann rearrangement, the Neber rearrangement, and N-amination reactions. It is not commercially available becuase it can detonate when it is concentrated to dryness. It has to be used with appropriate care when it needs to be used.

A similar reagent to MSH is O-(2,4-dinitrophenyl)hydroxylamine, which is relatively easy to handle and can be prepared on larger scales.

General References

Tamura, Y.; Minamikawa, J.: Ikeda, M. Synthesis 1977, 1. DOI: 10.1055/s-1977-24260
Erdik, E.; Ay, M. Chem. Rev. 1989, 89, 1947. DOI: 10.1021/cr00098a014

<O-(2,4-dinitrophenyl)hydroxylamine>

Legault, C.; Charette, A. B. J. Org. Chem. 2003, 68, 7119. DOI: 10.1021/jo034456l
Yang, Z. Synlett 2014, 25, 1186. DOI: 10.1055/s-0033-1341110

Reaction Mechanism
Examples

The total synthesis of pinnaic acid with the MSH-mediated Beckmann rearrangement as the key step.^[1]

The conversion of boronic acids to anilines.^[2]

The application to aziridine synthesis.^[3]

Experimental Procedure

The preparation of O-(2,4-dinitrophenyl)hydroxylamine.^[4]

Experimental Tips
References

Xu, S.; Arimoto, H.; Uemura, D. Angew. Chem. Int. Ed. 2007, 46, 5764. DOI:10.1002/anie.200701581
Zhu, C.; Li, G.; Ess, D. H.; Falck, J. R.; Kurti, L. J. Am. Chem. Soc. 2012, 134, 18253. DOI: 10.1021/ja309637r
Jat, J. L.; Paudyal, M. P.; Gao, H.; Xu, Q.-L.; Yousufuddin, M.; Devarajan, D.; Ess, D. H.; Kurti, L.; Falck, J. R. Science 2014, 343, 61. DOI:10.1126/science.1245727
Legault, C.; Charette, A. B. J. Org. Chem. 2003, 68, 7119. DOI: 10.1021/jo034456l