| Herein,an unreported iron-catalyzed system,which exhibits high efficiency,environmental friendliness and broad substrate scope,has been developed to construct C-Si and C-B bonds through inert C-O bond activation.Section 1.Iron-catalyzed construction of C-Si bonds via C-O bond activationIn this section,we have developed an iron-catalyzed system using simple iron salt Fe（OAc）2 as catalyst,XPhos as ligand,and Si Et3Bpin as silicon source in the presence of sodium methoxide,under which C-O bond of aryl carboxamide was activated to build C-Si bond and generated the desired aryl silicon compound efficiently.This reaction not only features high conversion rate and broad substrate scope,but also can realize the silylation reaction of natural product related compounds.What is more,the carbamate group can be used as a meta-directing group to generate polysubstituted aromatic C-H silylation products,providing good opportunities for applications in drug discovery and development.Section 2.Iron-catalyzed construction of C-B bonds via C-O bond activationIn this section,we have developed an iron-catalyzed system using simple iron salt Fe（OAc）2 as catalyst,TMEDA as ligand,and B2pin2 as boron source in the presence of t-Bu ONa,under which C-O bond of aryl carboxamide was activated to build C-B bond and generated the desired borylation compounds efficiently.It features high efficiency,broad substrate scope,enabling the late-stage borylation of bio-relevant compounds,thus providing a good method to access valuable motifs in medicinal chemistry.In addition,the desired borylation products can be obtained in gram scale.Moreover,this protocol enables palladium-catalyzed ortho or meta C-H bond functionalization and also allows for the synthesis of multi-substituted arenes due to carbamate group of phenol derivatives as the directing group.Preliminary mechanistic studies suggest that a FeⅡ/FeⅢ catalytic cycle via a radical pathway might be involved in the reaction. |
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