Terphenyls functions

A first milestone was the development of a novel intramolecular Diels-Alder cyclization of terphenyl monomers 38 and 41, containing both 4-phenylbuta-dienyl and styryl functions. The formation of the [4-1-2] cyclization adducts 39 and 42 is followed by a simple aromatization of the cyclohexene moieties [59]. In this way, the phenylated, two-dimensional arylene structures, 40 and 43,... 

Finally, attention is drawn to the extensive work of Okazaki and co-workers, wherein two terphenyl units have been attached to a central functionality in order to create novel all-carbon molecular bowl-like molecules.97 For example, the novel molecular bowl compound Ar Br (Ar Br = 2,6-bis(CH2C6H3-2,6-Dmp2)-4-/fT/-butyl-l-bromophenyl), was synthesized by a cross-coupling reaction between the Grignard reagent of the iodoterphenyl... 

Omer BP, Ernst JT, Hamilton AD. Toward proteomimetics terphenyl derivatives as structural and functional mimics of extended regions of an a-helix. J Am Chem Soc 2001 123 ... 

As an example, starting from m-terphenyls with other functionalities in 2 -position, other concave molecules with a m-terphenyl core are conceivable. Sulfur substituents have already been introduced into the 2 -position of a m-terphenyl, for instance X = SH, SOjH or SO2CI (see Section 6). A protected thiol functionality has already been incorporated into a concave thiol acetate 42 [28] (Scheme 7). 

Therefore structural units as the m-terphenyl moiety, which was used in the concave benzoic acids 38, would be useful if new functionalities could be placed in the 2 -position. In the case of the benzoic acid 33, the functional group (COOH) was incorporated by the reaction of the 2 -lithio compound 71 with CO2. But other electrophiles may also be used here [28]. Scheme 13 lists new m-terphenyls 72-75 whieh were obtained when electrophiles other than CO2 were used. Standard group transformations transferred these products into other 2 -substituted m-terphenyls 76-82 which are also listed in Scheme 13. 

In the thiol 79 and the sulfinic acid 80, two new acidic functionalities are now present in the 2 -position of a m-terphenyl system and should be incorporable into concave structures by a double bridging of the m-terphenyl. For the acetyl-protected thiol 78, the corresponding concave thiol acetate 42 (Scheme 7) could be obtained after tetrabromination of the four methyl groups and bridging with m-phenylenedithiol (see Sect. 2.3). 

Three doubly spin-labelled [2]catenanes with different sizes were studied by 4-pulse DEER.52 The experimental distribution of interspin distances was compared with a theoretical pair-correlation function computed based on geometrical constraints. In chloroform solution the medium and large catenanes were close to fully expanded, but in glassy o-terphenyl they were partially collapsed. For the smaller catenane there was a higher population of shorter interspin distances, which was attributed to interactions between unsaturated sections of the molecule. 

Fig. 60. Xanthene-functionalized terphenyl-based ligands for the sensitization of NIR emitting I. n ii...

TRICYCLIC p-TERPHENYLS (C-l 8 BASIC SKELETON) 2.1 Terphenyls bearing three oxygenated functions... 

Only two fungal p-terphenyls bearing three oxygenated functions are known, namely terferol (1), and its methylated analogue 2. 

Terphenyls bearing four or five oxygenated functions... 

Terphenyls bearing six oxygenated functions atromentin and analogues... 

Table IX. 50% Alkylene w-Terphenyl-4,4f -dicarboxylate/PTME w-Terphenyl-4,4/ -dicarboxylate Copolymers °—Properties as a Function of Diol Structure (36)...

Figure 16. Logarithmic plot of the diffusion coefficient D of o-terphenyl as a function of reciprocal temperature self-diffusion by gradient NMR (unfilled circles, filled circles, crosses), tracer diffusion data (unfilled triangles and squares) from forced Rayleigh scattering using photochromatic dye tracers, and inverse viscosity /x (line) the insert shows the product Dr /T note that the decoupling of diffusion and viscosity sets in around 290 K. (From Ref. 201, including data from Refs. 202 and 203.)...

Calix[4]arenes can be functionalized both at the phenolic OH groups (lower rim) and at the para positions of the phenol rings (upper rim).21 A special class of selectively functionalized calix[4]arenes comprises bridged calix[4]arenes in which two phenol rings are connected by a cap.22 An important subgroup of this class are the calixspherands in which a calix[4]arene is diametrically bridged with a rigid terphenyl moiety. 

Research is going on to improve the DELFIA system , because of drawbacks such as the time-consuming conversion of the non-fluorescent RE label into a luminescent complex, or the system vulnerability to contamination by RE due to the excess of the reagents ntfa and topo. An alternative is the use of a -diketone that can be covalently bonded to proteins such as 5-(4,4,4-trifluoro-l,3-dioxobutyl)-2-thiophenesulfonyl chloride (ctta) . Since the stability of the RE + complexes formed by this ligand is quite low, a large excess of RE + has to be used to shift the equilibrium to the rare-earth complex. More stable europium complexes can be obtained by the use of tetradentate fi-diketonates, such as 7a-7d, anchored on a functionalized o-terphenyl skeleton, or 8a-8c, anchored on a biperfluorobutadiene skeleton . ... 

The two coupling reactions appear to have a common free-radical intermediate. Functional groups already in the aromatic compound, Axil, orient ortbo-para regardless of their nature. The reactions are most valuable for the preparation of biaryls of unequivocal structure when the hydrocarbon, Ar H, is unsubstituted. Good directions are given for the synthesis of p-bromobiphenyl (35%), and the literature of the reaction has been reviewed. Among the hydrocarbons prepared in this way are a- and yS-phenylnaphthalenes, o-, m-, and p-methylbiphenyls and m- and p-terphenyls. Thiophene and pyridine nuclei also have been aryl-ated. ... 

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