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A rare, ruthenium‐catalyzed, oxazolinlyl assisted C−H functionalization and three‐component cascade cyclization for the synthesis of isoquinolinones via a metal‐carbene migratory insertion is reported. The transformation is unique since it involves the formation of multiple bonds in one pot via C−H functionalization and ring opening of oxazolines. Detailed mechanistic investigations reveal interesting insights on the mode of transformation, involving reversible C−H activation, migratory insertion of the diazo compound and cascade cyclization as the key step of the transformation. [ABSTRACT FROM AUTHOR]

We report herein an efficient and mechanistically unique tandem chemoselective 1,2-/1,4-migration of the thio group in keto thioesters that provides substituted butenolides in moderate to excellent yields. Thus, α-keto thioesters in the presence of stabilized phosphonate carbanions undergo tandem 1,2-sulfur migration; whereas 1,4-migration of the thio group has been achieved with the same thioesters after the treatment with Wittig reagents followed by BF3⋅OEt2-catalyzed tandem reaction. The crossover experiments and the isolation of intermediates reveal a stepwise mechanism for both of these transformations. [ABSTRACT FROM AUTHOR]

An efficient synthesis of polycyclic indole and pyrrole derivatives via a ruthenium-catalyzed intramolecular allylic dearomatization/migration reaction has been developed. This method features wide substrate scope, mild reaction conditions, and an operationally simple procedure. The capture of the spiro intermediate provides solid evidence for the dearomatization/migration reaction pathway. [ABSTRACT FROM AUTHOR]