A facile and efficient approach for the synthesis of spirooxindoles has been developed via the coupling of spirocyclic C, C-palladacycles with CH2Br2. The key spirocyclic palladacycles are generated catalytically via intramolecular remote C–H activation. A range of spirooxindoles can be synthesized in good to excellent yields from readily available starting materials.
Pd-Catalyzed Highly Regio- and Stereoselective Formation of C–C Double Bonds: An Efficient Method for the Synthesis of Benzofuran-, Dihydrobenzofuran-, and Indoline-Containing Alkenes
A highly regio- and stereoselective C–C double bond formation reactionvia Pd-catalyzed Heck-type cascade process with N-tosylhydrazones has been developed. Various N-tosylhydrazones derived from both ketones and aldehydes are found to be efficient substrates to provide di- and trisubstitutedolefins with high regio- and stereoselectivity. Furthermore, this reaction has a good functional group tolerance
Palladium-Catalyzed Tandem Reaction of Three Aryl Iodides Involving Triple C–H Activation
作者:Xiai Luo、Yankun Xu、Genhua Xiao、Wenjuan Liu、Cheng Qian、Guobo Deng、Jianxin Song、Yun Liang、Chunming Yang
DOI:10.1021/acs.orglett.8b00982
日期:2018.5.18
with two aryl iodides for the synthesis of spirooxindole has been achieved. The reaction underwent the process of triple C–Hactivation and four C–C bondformations based on the double trapping of transient spirocyclic palladacycles which are obtained through remote C–Hactivation.
spirocyclization forming spirooxindoles and spirodihydrobenzofurans has been achieved. Mechanistic studies suggest that the transformation proceeds through sequential carbopalladation, C–Hactivation, and benzyne insertion. Both classes of spirocycles have been synthesized in good to excellent yields, and the procedure is readily scalable.
A catalytic enantioselective domino Heck carbonylation reaction of o-iodoacrylanilides with phenylacetylenes or water has been developed using a Pd/(Cu) catalytic system containing a chiral diphosphine ligand L9, furnishing a wide array of chiral β-carbonylated 3,3-disubstituted oxindoles in high yields with up to 99 % ee values.