Catalysis inside Supramolecular Capsules: Recent Developments

Abstract

In the last decades, supramolecular chemists have developed new molecular receptors able to include a wide range of guests. In addition, they have designed synthetic hosts able to form capsules having an internal volume of thousands of Å3. This inner space shows different features from the bulk solution. In particular, this environment has recently been employed to perform chemical reactions, obtaining reaction products different from the “normal” conditions. These supramolecular capsules act as nanoreactors, catalyzing many chemical transformations. This review collects the recent developments (since 2015) in this field, focusing on supramolecular capsules based on resorcinarene hexameric capsules and metal-cage capsules.

Synthesis of a coumarin derivative of resorcin[4]arene with solvent-controlled chirality

“…12 Among other things, spatially developed structures such as cavitands, [13][14][15][16] dimeric capsules, [17][18][19][20] and hexamers [21][22][23][24] can be constructed based on such skeletons, and these can be used to study the reactivity of chemical compounds in spatially limited or closed structures. [25][26][27][28] One possibility for modifying the structure of resorcin [4] arene was our use of the methoxy derivative of resorcin [4]arene for the thermal generation of the o-quinone methide derivative of resorcin [4]arene, followed by a cycloaddition reaction [29][30][31] and Michael reaction with C, Pnucleophiles. 32,33 Until now, the synthesis of cyclochiral derivatives of resorcin [4]arene was based on two approaches: (1) structural modications of the skeleton of the resorcin [4]arene molecule via covalent bonds; 4,5 (2) on the selection of appropriate substrates for the synthesis of cyclochiral resorcin [4]arene molecules.…”

Size-Selective Catalytic Polymer Acylation with a Molecular Tetrahedron

“…Yet, despite various examples of protein posttranslational modifications (PTMs) catalyzed by enzymes, it remains a daunting task to create catalysts that can selectively recognize and modify man-made polymers. Thus, it has been a major goal of synthetic chemists to create supramolecular catalysts, [3][4][5][6][7] which can operate selectively on man-made polymers. 8,9 These efforts have led to the successful application of selective supramolecular catalysts for small-molecule transformations [10][11][12][13][14][15][16][17][18] as well as for growth 8,19,20 and functionalization 9,21 of linear polymers in a processive manner.…”

Modeling the Reaction of Carboxylic Acids and Isonitriles in a Self‐Assembled Capsule

“…Molecular cages are host compounds with interior cavities in which guests are confined in small spaces and shielded from interactions with the solvent. Such hosts have in many cases been found to act as reaction vessels, in which guests can react or undergo photochemical conversions . A special case is the class of containers called capsules, which are hosts that offer no or limited contact with solvent for their guests.…”