ChemInform Abstract: Acetylation of Triptycene and Ethyltriptycenes.

Abstract

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Structure‐Property Relationships for Potential Inversion From Electron Acceptors Based on Thiophene‐Fused Triptycene Quinones, 1,4‐Diketones and Their Malononitrile Adducts

“…Due to through‐space overlap of the π‐orbitals of adjacent fins the phenyl rings in triptycene are not electronically isolated from each other, therefore the influence of a strongly accepting moiety such as the para ‐quinones in 5 and 6 will make additions to subsequent rings of triptycene more challenging. This is supported by the fact that while the addition of less strongly deactivating carbonyl fragments to triptycene, such as formyl‐ or acetyl‐ groups, can be driven to form threefold addition products, increasingly forceful conditions are required for each subsequent addition [33–37] …”

“…The molecular and crystal structures are similar, in the same space group ðP � 1Þ and with adjustments to the unit cell parameters to accommodate solvent CDCl 3 . Pure 5 revealed two molecules in the asymmetric unit which form a close association via head-to-tail, but noncentrosymmetric, pairs of CÀ H•••π interactions H (34) S1). In the solvate 5 • 0.5(CDCl 3 ) there are also two quinone molecules and a molecule of deuterochloroform in the asymmetric unit.…”

“…This is supported by the fact that while the addition of less strongly deactivating carbonyl fragments to triptycene, such as formyl-or acetylgroups, can be driven to form threefold addition products, increasingly forceful conditions are required for each subsequent addition. [33][34][35][36][37] The diketones 5-7 thus obtained were then subjected to Knoevenagel condensation reactions with malononitrile using Lehnert's reagent (TiCl 4 /pyridine) [38,39] to introduce the dicyanomethylene moieties. While 5 was smoothly converted to bis(dicyanomethylene) 8 in 60 % yield, treating 6 in the same fashion halted at the oxo-dicyanomethylene 9 in a comparable yield of 58 %.…”

Synthesis, Structures, and Solid State Self-Assemblies of Formyl and Acetyl Substituted Triptycenes and Their Derivatives

“…It was known that acyl groups, especially formyl and acetyl groups, are a kind of important functional groups, and they can be transformed into various other useful organic functional groups. Although the selective introduction of the formyl and acetyl groups to triptycene skeleton is very important and attractive, few reports are known about them . Especially, except the synthesis of 2-acetyltriptycene reported by Paget and co-workers, no pure regioisomers of (2,6- or 2,7-)di-, (2,6,14- or 2,7,14-)triformyl and acetyl substituted triptycene derivatives were synthesized and well characterized so far.…”