Synthesis and X-ray Structure of Amide-Based Macrocycles, Catenanes and Pretzelane

Abstract

The syntheses and crystal structure studies of amide-based catenanes derived from m-phenylene diacrylic acid and 5acetoxy isophthalic acid (17% and 3% yield of 4a and 4b resp.) and octalactam macrocycles (21% yield of 3) are described. Hydrogen bonding patterns play a key role in the formation of the different conformations of octalactam 3. The crystal structures of 3 reveal a number of hydrogen-bonding [a] Kekulé-

Conformational Flexibility of Tetralactam Macrocycles and Their Intermolecular Hydrogen‐Bonding Patterns in the Solid State

“…The latter is essential for TLM‐containing [2]catenanes, which form an interesting network of six hydrogen bonds between the two wheels. This pattern is not only observed in the crystal structures6b, 15 of the final catenanes but is also believed to play a pivotal role in their templated synthesis 7. TLM 4 + is unique in being the only TLM so far that displays a 3‐ in ‐1‐ out conformation in the solid state without being incorporated in a catenane.…”

Synthesis and Characterization of a Catenated Polystyrene−Poly(2-vinylpyridine) Block Copolymer

“…The synthesis of topologically interesting molecules has attracted considerable attention in recently years. [1][2][3][4][5][6][7][8][9][10] Structures that cannot be represented without intersecting lines such as rotaxanes, 1,2 polyrotaxanes, [5][6][7][8][9][10] and catenanes [3][4][5][6][7] are particularly fascinating. The synthesis and study of such compounds frequently reveals interesting information on aspects of molecular architecture and intramolecular interactions and occasionally leads to new materials with unusual properties 7 (Scheme 1).…”

“…[3][4][5][6] Thus, Sauvage, Dietrich-Buchecker, and co-workers have developed an efficient synthesis of interlocked rings based on a transition metal mediated template that preposition the coordinating molecular threads leading to interlocked rings after cyclization. 3,4 The extensive work of Stoddart 5 and others has involved hydrogen bonding 7 and aromatic π-π stacking 6 as the key driving force for the assembly of cyclic structures.…”

Hydrogen-Bond-Mediated Template Synthesis of Rotaxanes, Catenanes, and Knotanes

“…The "magic rod" experiment for preparation of rotaxanes from intact axles and wheels through a reversible olefin metathesis reaction introduction of a covalent bridge between the two components leads to new topologies, i.e., pretzelanes [170,171] and [1]rotaxanes [172]. This was accomplished through replacement of one or more of the amide groups incorporated in the axle and wheel by sulfonamide groups [173], which can be deprotonated more readily and thus permit selective alkylation.Alternatively, substitution of the catenane macrocycles with OH groups at the isophthalic acid derivatives permits the reaction with an alkyl diiodide to yield the pretzelane.…”