Cyclization-Carbonylation of 2-Alkynyl Primary Benzamides using
p-Benzoquinone under Neutral Conditions.
J Org Chem 2024;
89:3977-3986. [PMID:
38407947 DOI:
10.1021/acs.joc.3c02812]
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Abstract
A palladium-catalyzed cyclization-carbonylation of 2-alkynyl primary benzamides 1 afforded methyl 3-substituted 1-methoxyisoquinoline-4-carboxylates 6 in good to moderate yields. In the case of mesylate 1r, 12 was obtained directly via a cyclization-carbonylation-cyclization cascade. Compounds 6 were converted to isoquinolin-1(2H)-ones 8 in good yields under microwave irradiation. In the case of the mesylate 6q, tricyclic isoquinolinone 10 was obtained in good yield. The reactions of thiophene-2-carboxamide derivatives also proceeded well.
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