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Benzylic Aroylation of Toluenes Mediated by a LiN(SiMe3)2/Cs+ System

Yuanyun Gu, Zhen Zhang, Yan-En Wang, Ziteng Dai, Yaqi Yuan, Dan Xiong, Jie Li, Patrick J. Walsh* and Jianyou Mao*

*University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States; Nanjing Tech University, Nanjing 211816, P. R. China, Email:,

Y. Gu, Z. Zhang, Y.-E. Wang, Z. Dai, Y. Yuan, D. Xiong, J. Li, P. J. Walsh, J. Mao, J. Org. Chem., 2022, 87, 406-418.

DOI: 10.1021/acs.joc.1c02446


Bimetallic LiN(SiMe3)2/Cs+ combinations exhibit excellent benzylic selectivity in deprotonative additions of toluenes to Weinreb amides for the synthesis of a diverse array of 2-arylacetophenones. Surprisingly, simple methyl benzoates also react with toluenes under similar conditions to form 2-arylacetophenones without double addition to give tertiary alcohol products.

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Double addition does not occur because the base rapidly deprotonates the ketone to give the enolate, which is inert to further additions.

Patrick J. Walsh, Jianyou Mao, October 3, 2022

Key Words

acylation, benzylation, Weinreb Ketone Synthesis

ID: J42-Y2022