Ortho lithiation-in situ borylation of substituted morpholine benzamides

Morpholine amides are cheap and safe alternative to Weinreb amides as acylating agents of organometallic species. Herein, the in-situ lithiation/borylation of 18 ortho- meta- and para-substituted morpholine benzamides has been investigated. 10 of the 18 substrates provided the desired boronic esters as the major isomer (>90% regioselectivity) in crude isolated yields ranging from 68 to 93%. The synthetic usability of such building blocks was subsequently illustrated via the synthesis of a kinase inhibitor.

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