Silver-Catalyzed C(sp2)–H Functionalization/C–O Cyclization Reaction at Room Temperature
摘要:
Silver-catalyzed C(sp(2))-H functionalization/CO cyclization has been developed. The scalable reaction proceeds at room temperature in an open flask. The present method exhibits good functional-group compatibility because of the mild reaction conditions. Using a AgNO3 catalyst and a (NH4)(2)S2O8 oxidant in CH2Cl2/H2O solvent, various lactones are obtained in good to excellent yields. A kinetic isotope effect (KIE) study indicates that the reaction may occur via a radical process.
An efficient and robust methodology based on electrochemical techniques for the direct synthesis of aromatic lactones through dehydrogenative C−O cyclization is described. This new and useful electrochemical reaction can tolerate a variety of functional groups, and is scalable to 100 g under mild conditions. Remarkably, heterocycle‐containing substrates can be employed, thus expanding the scope of
Novel and Efficient One-Step Parallel Synthesis of Dibenzopyranones via Suzuki−Miyaura Cross Coupling
作者:Kodumuru Vishnumurthy、Alexandros Makriyannis
DOI:10.1021/cc100068a
日期:2010.9.13
Microwave-promoted novel and efficient one-step parallel synthesis of dibenzopyranones and heterocyclic analogues from bromo arylcarboxylates and o-hydroxyarylboronic acids viaSuzuki−Miyauracrosscoupling reaction is described. Spontaneous lactonization gave dibenzopyranones and heterocyclic analogues bearing electron-donating and -withdrawing groups on both aromatic rings in good to excellent yields