Addition to the carbon-nitrogen multiple bonds

Grignard reagents add with difficulty to imines derived from enolizable carbonyl compounds. Improvements such as the activation of the C=N bond can be achieved either by attachment of an electron-withdrawing group or 

A convenient synthesis of aryl glycines from Grignard reagents, prepared via iodine-magnesium exchange, was performed by the reaction with N-Boc-iminomalonate (from diethyl mesoxalate and BocN=PPh3). The reaction 

This reaction has also been applied to the synthesis of a-amino acids.295,295a 295b In the case of the sulfinimines derived from simple ketones, lithium reagents are preferable for the addition,2943 although for cyclic ketones, organomagnesium compounds gave better results. The addition of alkyl and aryl Grignard compounds to 

The presence of a coordinating group in the sulfinimine may strongly influence the selectivity of the reaction with Grignard derivatives. In the case of 2-pyridyl ftrt-butylsulfinimines, the diastereoselectivity of the addition is reversed due to the coordination with the pyridine nitrogen. Attempts have been made to prepare sulfinyl chiral 

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