Pd-Catalyzed Bidentate Directing Group Promoted Functionzlization Of C-H Bond And Application Research

Transition-metal-catalyzed directing group-promoted C-H bond activation and functionalization has attracted tremendous interest owing to its highly selectivity and atom-economic advantages over the past decades.Comparing with the monodentate directing group generally works on C?sp²?-H activation,the bidentate directing groups have been demonstrated that they are able to promote metal-catalyzed C?sp³?-H bond activation.How to bulid a removable and highly effiency bidentate directing group becomes a hot topic in the C-H bond activation field.This paper focused on the studies of Pd-catalyzed bidentate directing group promoted functionzlization of C-H bond and application research,which includes:1.Pd???-catalyzed C?sp³?-H arylation of amino acid derivatives with click-triazoles as removable directing groupThe click-triazoles has shown great metal-coordinate ability in recent years.By using click-triazoles as a conveniently approachable and removable directing group,the direct palladium-catalyzed C?sp³?-H arylation of amino acid derivatives with various aryl iodides bearing different electronic properties has been achieved.Notably,the desired amino acid molecular can be obtained with excellent enantiopurity by the easy cleavage of the tethered click-triazoles after the catalytic reaction,which aims to provide a practical protocol for the accessibility of both nature and synthetic amino acids.2.Pd/C-catalyzed C?sp²?-H arylation with click-triazoles as removable directing groupA novel protocol for Pd/C catalyzed C?sp²?-H arylation of benzamides with good functional group compatibility under silver-free conditions by using click-triazoles as a removable directing group has been first developed.Desired product could be obtained by using the recycled Pd/C as the catalyst in two runs.3.The application of Pd-catalyzed directing group promoted functionzlization of C-H bondTo highlight the synthetic utility of C-H bond activation,we then studied the synthesis of two fine chemistry intermediate by using this protocol.First,the key intermediate of angiotensin II receptor antagonists 2-cyano-4-methylbiphenyl was synthesized with shorter route and lower pollution by using Pd?OAc?₂-catalyzed C-H bond activation method.Second,we realized the Pd/C-catalyzed C-H bond iodation of benzamide derivative,thus synthesized the key intermediate of flubendiamide with great efficiency and selectivity.