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[摘要]:A one-pot reaction involving an aldehyde, a methyl ketone, and the Bestmann-Ohira reagent has been developed for the synthesis of variously substituted 3-carbo-5-phosphonylpyrazoles. Our synthetic methodology features a domino Claisen-Schmidt/1,3-dipolar cycloaddition/oxidation sequence, which leads to the target compounds in excellent yields. We further demonstrated that this unprecedented sequence could also be combined with a copper-catalyzed azide-alkyne cycloaddition in a one-pot, four-step cascade process generating five new bonds and two heterocyclic rings. |
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