Preparation of polyfunctional arylzinc organometallics in toluene by halogen/zinc exchange reactions

Balkenhohl, Moritz and Ziegler, Dorothée S. and Desaintjean, Alexandre and Bole, Leonie J. and Kennedy, Alan R. and Hevia, Eva and Knochel, Paul (2019) Preparation of polyfunctional arylzinc organometallics in toluene by halogen/zinc exchange reactions. Angewandte Chemie International Edition, 58 (37). pp. 12898-12902. ISSN 1433-7851 (https://doi.org/10.1002/anie.201906898)

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Abstract

A wide range of polyfunctional diaryl-and diheteroarylzinc species were prepared in toluene within 10 min to 5 h through an I/Zn or Br/Zn exchange reaction using bimetallic reagents of the general formula R’2Zn·2LiOR (R’=sBu, tBu, pTol). Highly sensitive functional groups, such as a triazine, a ketone, an aldehyde, or a nitro group, were tolerated in these exchange reactions, enabling the synthesis of a plethora of functionalized (hetero)arenes after quenching with various electrophiles. Insight into the constitution and reactivity of these bimetallic mixtures revealed the formation of highly active lithium diorganodialkoxyzincates of type[R’2Zn-(OR)2Li2].