The direct catalyst-free, displacement of aryl alkoxy groups has been used in the synthesis of substituted aromatic rings in the presence of ketones and esters. In a recent work,1we reported the displacement reaction of a series of 1-alkoxy-2-naphthoic methyl esters with a variety of Grignard reagents. Almost exclusive displacement of the methoxy group at the 10-position was observed, with no observable addition to carbonyl moiety. Through this work, the direct displacement of alkoxy groups from aromatic and a,�-unsaturated esters and ketones was demonstrated to be an efficient C�C bond-forming process with minimal use or protecting groups. The displacement of alkoxy groups adjacent to esters in naphthyl esters is affected by the steric demand of both the Grignard reagent and the alkyl group of the ether. In this communication, a thorough theoretical study on the mechanisms of Grignard displacement of aryl alkoxy groups and nucleophilic addition to carbonyls in order to rationalize the observed selectivity, is reported. As the displacement reaction is unique to organomagnesium compounds, the formation of a transiently formed magnesium chelate was investigated. An excellent agreement was found between experimental and computational results, which allowed also predicting the correct chemoselectivity in similar reactions with different substrates.1 A. J. Brockway, M. Gonz�lez-L�pez, J. C. Fettinger, and Jared T. Shaw J. Org. Chem., 2011  , 76, 3515.

Computational insights into the direct displacement of alkoxy groups of vinylogous esters by Grignard reagents

245th National Meeting (2013)

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