Synthesis, Structure and Conformation of Terphenylene‐Derived Oxacalixaromatics

Abstract

Oxacalix[4]aromatics comprised of terphenylene units have been synthesized by cyclooligomerization of 5′‐tert‐butyl‐1,1′:3′,1″‐terphenyl‐4,4″‐diol (1) and electron‐deficient meta‐dihalogenated benzene and heterocycles. Single‐crystal X‐ray analysis revealed that oxacalix[2]terphenylene[2]pyrazine 13 adopts a chair conformation, forming a molecular cavity to trap an ethyl acetate guest molecule in the solid state. 1,3‐Alternate conformations are adopted by other oxacalix[2]terphenylene[2]aromatics (11, 12 and 15), which form a narrow tweezer‐like molecular cavity that is incapable of encapsulating any guest molecules.

Sequential One-Pot Access to Molecular Diversity through Aniline Aqueous Borylation

“…Following the general procedure A, 1j was obtained from 4-(benzyloxy)aniline 25 (199.2 mg, 1.0 mmol) as a white solid (57.3 mg, 25%). The 1 H and 13 C data were consistent with those reported in the literature: 26 2-Nitrophenylboronic acid (1k). Following the general procedure A, 1k was obtained from 2-nitroaniline (138.1 mg, 1.0 mmol) as a brown solid (46.2 mg, 28%).…”

“…Following the general procedure A, 1j was obtained from 4-(benzyloxy)aniline (199.2 mg, 1.0 mmol) as a white solid (57.3 mg, 25%). The 1 H and 13 C data were consistent with those reported in the literature: ν max (film)/cm –1 3363 (br), 2479, 1604, 1337 (br), 1245, 1176, 1110, 1009, 821, 749, 704; 1 H NMR (400.0 MHz; Acetone- d 6 + D 2 O) δ H = 7.80 (d, J = 8.6 Hz, 2H, ArH), 7.44 (d, J = 7.8 Hz, 2H, ArH), 7.36 (t, J = 7.8 Hz, 2H, ArH), 7.29 (t, J = 7.8 Hz, 1H, ArH), 6.96 (d, J = 8.6 Hz, 2H, ArH), 5.09 (s, 2H, CH 2 ); 13 C NMR (100.6 MHz; Acetone- d 6 + D 2 O) δ C = 161.4 (ArC), 138.1 (ArC), 136.7 (2 × ArCH), 129.2 (2 × ArCH), 128.6 (ArCH), 128.3 (2 × ArCH), 114.7 (2 × ArCH), 70.1 (CH 2 ); 11 B NMR (128.4 MHz; Acetone- d 6 + D 2 O) δ B = 28.6 (br s).…”

Synthesis and Evaluation of Nifurtimox–Adamantane Adducts with Trypanocidal Activity

“…O-Demethylation of 24 led to the desired phenol 19 in 52 %o verall yield (from adamantanone 22). The second reaction pathway involved lithiationo ft he aryl bromide 25, [26] whichw as added to the 2-adamantanone (22)t o give the 2-(4-(benzyloxy)phenyl)adamantan-2-ol (26). This was sequentially reduced and hydrogenated to give 4-(2-adamantyl)phenol (19)i n2 5% overall yield (from the aryl bromide 30).…”

“…Due to the inefficiency of the published methods for the preparation of 4-(2-adamantyl)phenol ( 19), we developed the alternative synthetic routes to 19,shown in Scheme4. The second reaction pathway involved lithiationo ft he aryl bromide 25, [26] whichw as added to the 2-adamantanone (22)t o give the 2-(4-(benzyloxy)phenyl)adamantan-2-ol (26). O-Demethylation of 24 led to the desired phenol 19 in 52 %o verall yield (from adamantanone 22).…”

A Trigonal Prismatic Ligand in the Metal-Mediated Self-Assembly of One- and Two-Dimensional Metallosupramolecular Polymers

“…Much efforts have therefore been devoted to rationalize the ligand design for controlling the geometries and functionalities of the resulting metal–ligand assemblies. − Conformational well-defined macrocyclic compounds, such as calixarenes, resorcinarenes, and cyclotriveratrylenes, have been playing a very important role in host–guest chemistry. , The integration of metal binding sites into these macrocyclic compounds led to macrocyclic ligands that have been successfully used in the metal-mediated self-assembly of nanosized coordination cages, − interlocking catenating assemblies, and “Solomon cube” . Previously, we and others have succeeded in the synthesis of heteracalixaromatics, with exo -nitrogen-heterocyclic termini, and the investigation of the coordination-driven self-assembly based on these heteracalixaromatic ligands led to the generation of metallomacrocyclic cages and coordination polymers . Recently, heterabicyclooxacalixaromatics, conformationally restricted analogues of heteracalixaromatics with a trigonal prismatic cage-like structure of high symmetry have been synthesized.…”