A Straightforward Access to Cyclotriveratrylene Analogues with C₁ Symmetry: Toward the Synthesis of Monofunctionalizable Cryptophanes

Abstract

A straightforward and practical access to various C1‐symmetric cyclotriveratrylene derivatives from a monohalogenated cyclotriphenolene is described. This unique scaffold can be used as a precursor for the rapid construction of monofunctionalizable cryptophane‐based biosensors for hyperpolarized 129Xe MRI.

Controlled Access to C1‐Symmetrical Cyclotriveratrylenes (CTVs) by Using a Sequential Barluenga Boronic Coupling (BBC) Approach

“…Whereas the synthesis and the utility of C 3 ‐symmetrical CTVs are well defined in the literature, the preparation and uses of C 1 ‐symmetrical derivatives have been less studied. To date, the most efficient approach to access C 1 ‐symmetrical CTVs is to desymmetrize C 3 ‐symmetrical CTVs (Scheme 1, A) either by performing direct halogenation [18] or by modifying the nature of a substituent on one of the aromatic rings [30,31] . Using the same strategy, modification of the apical positions has also been described through an oxidation to the corresponding ketone [32] followed by further transformations such as Beckmann rearrangement [33] .…”

“…C 3 -Symmetrical CTVs have found a wide variety of uses as ion or organic molecule sensors [2,3] building blocks for liquid crystals [3] or purification devices. [4][5][6] CTVs are also known to be precursors in supramolecular assemblies such as capsules, [7][8][9] cryptophanes [10][11][12][13][14][15][16][17][18] and hemicryptophanes. [19][20][21][22][23][24][25][26] To date, most of these applications are based on the use of C 3symmetrical CTVs and, for decades, C 3 -symmetrical CTVs have been synthesized from the corresponding substituted benzylic alcohols through cyclotrimerization using acidic conditions such as perchloric acid in methanol, [27] sulfuric acid in acetic acid, [10] formic acid [28] or scandium triflate.…”

Attempted Resolution and Racemization of Beckmann‐Derived CTV‐Lactam and the Use of Chirabite‐AR® to Determine the Optical Purity of the Supramolecular Scaffold

“…While most work with CTV has focused on peripheral functionalization, we have focused on apical functionalization, enabling attachment of CTV “bowl‐out” receptors on surfaces, including desymmetrized C 1 ‐symmetric derivatives that are also of interest . The parent nine‐membered cyclophane 1 (Figure ) is locked under ambient conditions in the bowl‐shaped crown conformer.…”

Cyclotribromoveratrylene in synthesis of porphyrin-containing polyphenols

“…В последние десятилетия бурное развитие супрамолекулярной химии с использованием комплексов "хозяин-гость" сопровождается постоянным интересом к циклотривератрилену (ЦТВ) как конвергентному соединению типа "хозяин" со сходящимися центрами связывания [1][2][3]. Циклотривератрилен представляет собой циклический тример вератрола с трибензо[a, d, g]циклононатриеновым центральным звеном, характеризующийся наличием открытой молекулярной полости.…”

“…К тому же арильные кольца ЦТВ богаты электронами вследствие электронодонорных свойств метоксизаместителей, что дополняет электронодефицитную природу соединения С 60 . Указанные выше свойства "хозяина" позволяют ЦТВ образовывать различные супрамолекулы "хозяин-гость", что открывает широкие возможности для применения этих комплексов в таких процессах, как разделение смесей фуллеренов, молекулярное распознавание, образование жидких кристаллов и органических гелей, а также в сенсорной химии [2,3].…”