Divergent Synthesis of Chiral Covalent Organic Frameworks

Abstract

Featuring the simultaneous generation of alibrary of compounds from ac ertain intermediate,d ivergent synthesis has found increasing applications in the construction of natural products and potential medicines.I nspired by this approach, presented herein is ageneral strategy to introduce functionality, in ad ivergent manner,i nto covalent organic frameworks (COFs). This modular protocol includes two stages of covalent assembly,t hrough which functional COFs can be constructed by athree-step transformation of akey platform molecule,such as 4,7-dibromo-2-chloro-1H-benzo[d]imidazole (DBCBI). Constructed herein are four types of chiral COFs (CCOFs) from DBCBI by nucleophilic substitution, Suzuki coupling, and imine formation. The unique arrayofeight isoframework CCOFs allowed investigation of their catalytic performance and structure-activity relationship in an asymmetric amination reaction.

Covalent Organic Frameworks (COFs) for Cancer Therapeutics

“…More importantly, COFs are not easily influenced by the environment, especially in aqueous biological media. Versatility: Owing to the diversity of organic reactions, the functionalization of COFs is relatively easy. In addition to various functionalized monomers, covalent‐bonding‐driven COFs can tolerate more types of organic transformations, moreover, a greater variety of functional organic molecules can be introduced into the COF framework by post‐synthetic modification (PSM) Biocompatibility: COFs are metal‐free, allowing metal‐related, especially the heavy‐metal‐related, potential toxicity to be entirely avoided.…”

“…Versatility: Owing to the diversity of organic reactions, the functionalization of COFs is relatively easy. In addition to various functionalized monomers, covalent‐bonding‐driven COFs can tolerate more types of organic transformations, moreover, a greater variety of functional organic molecules can be introduced into the COF framework by post‐synthetic modification (PSM)…”

Chiral covalent organic frameworks: design, synthesis and property

“…1). 28,[72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90] (1) Post-synthesis: synthesis of CCOFs from achiral parent COFs by post-synthetic modification of the organic framework.…”

Recent Advances in Covalent Organic Frameworks for Catalysis

“…[32][33][34][35] However,t he ionothermal synthesis requires high reaction temperature, which limiting its wide-ranging application.A sa clean and fast synthetic methods, microwave heatings ynthesis offers new facilities for furtherl argescale application. [39][40][41][42] According to the structuralp roperties of the buildingb lock,the majority of the COFs synthesized to date are generally categorized into three classes,n amely,b oron-containing COFs, nitrogen-containing COFs and silicon containing COFs. Moreover,a sacrystalline porousm aterialc atalyst, the covalent frameworkm ay be coordinated with as eries of metal ions, functional groups and even ionic liquids, et.al.…”

“…Thus catalytic sites can be successfully incorporated into the organic skeleton or layer spacesw ithoutc ompromising the crystallinity of COFs, which also arousing great interesti nh eterogeneous catalysis. [39][40][41][42] According to the structuralp roperties of the buildingb lock,the majority of the COFs synthesized to date are generally categorized into three classes,n amely,b oron-containing COFs, nitrogen-containing COFs and silicon containing COFs. [34,[44][45] Figure 2s ummaries the representational examples of boron, nitrogen, and silicon-containing COFs.F or the boron-containing COFs, organic units are linked by either boroxinel inkages or boronate esters linkages.…”