MC Strecker Reaction

SCHEME 10.13 Synthesis of dimers 53 and 54 from cis-SS and trans-56 spirocyclic linkers, respectively. 

SCHEME 10.15 Strecker synthesis of a-amino acid via a-aminonitriles. 

Although some interesting reviews have appeared in the last years coveting this appealing area of research in the field of organocatalysis [48c, 53] and metal catalysis [48d, 51], we will try to rertrark in this section the most important examples since 2005. 

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Various fluorinated and nonfluorinated ketones were successfully employed in this MC Strecker reaction, and interestingly, the proper choice of the reaction conditions (catalyst and solvent) was crucial for the achievement of the process with very good results. Later, this research group developed a similar procedure using TMSOTf [63] or Nafion -H [64] as efficient catalysts of this reaction. 

The MC Strecker reaction is the key step in this synthesis for the preparation of intermediate aminonitrile 81 further acylation of that compound with benzothiadiazine acid 82 under the standard conditions followed by in situ addition of triethylamine provided the desired aminotetramic acid 83. 

Although the Strecker reaction has been extensively studied with aldehydes using various kinds of catalysts and types of catalysis, the MC version nsing ketones has been less explored, maybe due to the less reactivity shown by these substrates, and only in 2007 it was reported the first efficient and extensively developed strategy using gallium triflate as catalyst (Scheme 10.25) [62]. 

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