Veguillas M, Ribagorda M, Carreño MC. Regioselective alkylation of heteroaromatic compounds with 3-methyl-2-quinonyl boronic acids.
Org Lett 2011;
13:656-9. [PMID:
21218792 DOI:
10.1021/ol1028964]
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Abstract
Reactions of heteroaromatic compounds with 3-methyl substituted 2-quinonyl boronic acids proceeded by 1,4-addition followed by spontaneous protodeboronation, leading directly to the Friedel-Crafts alkylation products instead of the commonly observed alkenylation derivatives resulting from quinones. The boronic acid acts as a temporary regiocontroller, making the system a highly reactive quinone equivalent and opening a direct access to 5,5-disubstituted cyclohexene-1,4-diones.
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