Covalent organic frameworks and multicomponent reactions: an endearing give-and-take relationship

Abstract

Covalent organic frameworks (COFs) are porous and crystalline materials which are assembled by dynamic covalent bonds with two- or three-dimensional (2D or 3D) features. Unlike other polymers, COFs have significant...

Building Blocks and COFs Formed in Concert—Three‐Component Synthesis of Pyrene‐Fused Azaacene Covalent Organic Framework in the Bulk and as Films

“…In recent years, the three-component synthesis has emerged as a powerful methodology for the synthesis of functional COFs. [2,3] Early reports mainly focused on the synthesis of dual-linkage COFs, which incorporate both imine and boronic ester linkages in their final structure. [4] Subsequent studies explored the stabilization of reactive imine bonds.…”

“…[13,16] Therefore, developing techniques to assemble these aromatic molecules in an ordered manner, as powders and films, is crucial for their characterization and practical utilization. [2,17] Very recently, we presented a PSM approach to incorporate pyrene-fused azaacene moieties into a COF, using 2D Dione-COF as precursor. [18] This method achieved up to 33 % conversion of the dione moiety.…”

“…[5] Notably, our approach also allows for the three-component synthesis of functional frameworks as thin films, which had not been demonstrated with existing three-component methodologies thus far. [2] In practice, the pyrene dione building block [19] was allowed to react with various diamines in the course of the COF formation to form the respective azaacenes. Impressively, the conversion of the dione moiety is quantitative, and the resulting COF powders, termed Aza-Ph-, Aza-Naph-, and Aza-2Ph-COF, feature accessible surface areas and long-range order.…”

“…For the PSM approach, the framework stability under the employed functionalization conditions and the reaction yield are among the primary considerations. In recent years, the three‐component synthesis has emerged as a powerful methodology for the synthesis of functional COFs [2, 3] . Early reports mainly focused on the synthesis of dual‐linkage COFs, which incorporate both imine and boronic ester linkages in their final structure [4] .…”

Six‐Component Reactions and Beyond: The Nuts and Bolts

“…[110] These synthetic materials have demonstrated applications from catalysts [111,112] and biosensors [113] to water treatment [114] and enzyme immobilization [115] (Figure 4). More recently, MCR methodologies have been implemented in leading-edge materials encompassing chromophores, [116] metal organic frameworks [117] , covalent organic frameworks [118] , functionalized cellulose [119] , ligation and bioconjugation chemistry [120,121] and other advanced interdisciplinary applications [122][123][124] . Moreover, many examples of MCRs exist in the pharmaceutical sciences, [31,125] where these efficient synthetic strategies have been applied in drug delivery, [126] gene delivery, [127,128] drug design [129] and pharmaceutics, [130][131][132] agrochemicals.…”