Palladium-Catalyzed Oxidative Cross-Coupling of N-Tosylhydrazones with Indoles: Synthesis of N-Vinylindoles
摘要:
A general and efficient palladium-catalyzed oxidative cross-coupling reaction of N-tosylhydrazones with indoles providing N-vinylindoles has been developed. The reaction proceeds smoothly with various indoles and N-tosylhydrazones in a stereocontrolled manner, and a wide variety of N-vinylindoles were obtained up to 99% yields for 26 examples.
A protocol for the synthesis of terminal N-vinylazoles from aromatic aldehydes, DMSO, and azoles has been reported. In this strategy, DMSO was involved in the construction of the C=C bond as a terminal carbon synthon. Both aromatic aldehydes and azoles could be well tolerated and give the corresponding terminal N-vinylazoles in 52–91% yields. Based on preliminary experiments, a plausible mechanism