Pd-Catalyzed Oxidative Coupling of Enamides and Alkynes for Synthesis of Substituted Pyrroles
摘要:
A novel and efficient palladium(II)-catalyzed alkenyl C-H activation oxidative annulation of enamides with alkynes for the synthesis of substituted pyrroles has been developed. The reaction tolerates a wide range of functional groups and is a reliable method for the synthesis of triaryl-substituted pyrroles in high yields.
MnO2-Catalyzed Oxidative Alkylation of Enamides with Ethers via C(sp3)–H/C(sp2)–H Cross-Dehydrogenative Coupling and Hydrolysis Sequence
作者:Xiangsheng Xu、Zhiyan Hu、Yucai Tang、Shan Zhang、Xiaoqing Li、Xiaohua Du
DOI:10.1055/s-0035-1560180
日期:——
A new MnO2-catalyzed oxidative alkylation of enamides with a C(sp3)–H bond adjacent to an oxygen atom is described. This method achieves a C(sp3)-H/C(sp2)-H cross-dehydrogenative coupling and hydrolysis, thus providing efficient and general access to a variety of β-oxo ketones.
is a fundamental concept in organic chemistry, which provides an alternative strategy for the synthesis of target compounds which were not easily accessible by conventional methods. Herein, a mild and efficient PhI(OAc)2-promoted umpolung acetoxylation reactions of enamides was developed for the synthesis of α-acetoxy ketones. The reaction tolerates a wide range of functional groups and affords α-acetoxy
addition-cyclization-elimination cascade is developed, that allows various 2,6-diaryl-4-perfluoroalkylpyridines to be synthesized in one step from easily available enamides and perfluorocarboxylic anhydrides. The procedure is also operationally simple and scalable and provides access to the facial construction of 4-fluoroalkylpyridines, which are of great interest in medicinal chemistry.
only: An atom‐economical synthetic route towards arylated Z‐enamides through double CH functionalization is described. The Z/E selectivity of the palladium‐catalyzed monoarylation is absolute (step A in scheme), and the molecular complexity of the products can be further endowed by a sequential second arylation, which requires the use of trifluoracetic acid (TFA; step B).