Adamantane-1,3,5,7-tetracarboxylic acid

Kollner et al. (29) prepared a Josiphos derivative containing an amine functionality that was reacted with benzene-1,3,5-tricarboxylic acid trichloride (11) and adamantane-l,3,5,7-tetracarboxylic acid tetrachloride (12). The second generation of these two types of dendrimers (13 and 14) were synthesized convergently through esterification of benzene-1,3,5-tricarboxylic acid trichloride and adamantane-1,3,5,7-tetracarboxylic acid with a phenol bearing the Josiphos derivative in the 1,3 positions. The rhodium complexes of the dendrimers were used as chiral dendritic catalysts in the asymmetric hydrogenation of dimethyl itaconate in methanol (1 mol% catalyst, 1 bar H2 partial pressure). The enantioselectivities were only... 

The self complementary 8.59 may be regarded as the logical three-dimensional progression of the topological zero-, one- and two-dimensional points, chains and sheets formed by benzoic acid, tereph-thalic acid and trimesic acid (Section 7.4.1), shown schematically in Figure 8.77. Adamantane-1,3,5,7-tetracarboxylic acid (8.59) forms a diamondoid network with cavities so large that close packing can... 

A second strategy is to place multiple chiral Josiphos-type (329) units along the exterior of dendrimers, and successful applications for rhodium-catalyzed asymmetric hydrogenation utilize cores composed of benzene-1,3,5-tricarboxylic acid esters (381), adamantane-1,3,5,7-tetracarboxylic acid esters (382), and cyclophosphazenes see Phosphazenes) (383). Enantioselectivities are excellent and these dendrimeric materials can be recovered by filtration through a nanofiltration membrane. 

Powell). The solid lines represent hydrogen bonds, (b) Interpenetrated two-dimensional networks in trimesie aeid. (c) Interpenetrated three-dimensional networks in adamantane-1,3,5,7-tetracarboxylic acid. View this art in color, at www.dekker.com.)... 

Ermer, 0. Five-fold diamond structure of adamantane-1.3.5.7-tetracarboxylic acid. J. Am. Chem. Soc. 1988. 110. 

Figure 16 Benzoic acid dimer (a), trimesic acid trigonal network (b), and adamantane-1,3,5,7 tetracarboxylic acid diamondoid network (c) via the carboxylic acid dimer...

Scheme 4.37. Construction of dendrimers using the tetravalent core-adamantane tetracarboxylic acid.

Recently Togni et al. [19] focussed on the preparation of asymmetric dendrimer catalysts derived from ferrocenyl diphosphine ligands anchored to dendritic backbones constructed from benzene-1,3,5-tricarboxylic acid trichloride and adamantane-l,3,5,7-tetracarboxylic acid tetrachloride (e.g. 11, Scheme 11). In situ catalyst preparation by treatment of the dendritic ligands with [Rh(COD)2]BF4 afforded the cationic Rh-dendrimer, which was then used as a homogeneous catalyst in the hydrogenation reaction of, for example, dimethyl itaconate in MeOH. In all cases the measured enantioselectivity (98.0-98.7%) was nearly the same as observed for the ferrocenyl diphosphine (Josiphos) model compound (see Scheme 11). 

Dioxoadamantane-l,3,5,7-tetracarboxylic acid reacts with sulfur tetrafluoride in a conventional way to give high yields of 2,2,6,6-tetrafluoro-1,3,5,7-tetrakis(trifluoromethyl)adamantane... 

The first attempt towards three-dimensional diamondoid, tetrahedral networks was made with adamantane-l,3,5,7-tetracarboxylic acid. Interpenetration of five different networks, however, precluded the formation of internal chambers. A more open structure with large chambers was obtained from the tetra-2-pyridone methane called tecton . Its diamondoid lattice entrapped butyric acid (Figure l.lTf. ... 

Carboxylic acids, such as adamantane-l,3,5,7-tetracarboxylic acid [43] and tetrapyr-idones (silane and carbon based) [44, 45], have been employed in the construction of 3-D diamondoid networks through self-complementary interactions, Scheme... 

Finally, carbamazepine tetracarboxylic acid-adamantane [115] represents one of the few examples of clearly defined and predictable 3-D motif observed in a hydrogen-bond-based binary co-crystal. 

Figure 4 Some hydrogen-bonding patterns in crystalline carboxylic acids. The dimer motif is used in terephthalic acid, trimesic acid and adamantane-l,3,5,7-tetracarboxylic acid to obtain networks of increasing dimensionality...

The advantage of using the synthon approach is that it offers a considerable simpHfication in the understanding of crystal structures. For example, the same carboxy dimer motif 1 is present in the structures of benzoic acid, terephthalic acid, isophthahc acid, trimesic acid and adamantane-l,3,5,7-tetracarboxylic acid in zero-, one-, two- and three-dimensional arrangements [9] (see also the article by R. E. Melendez and A. D. Hamilton in this volume). 

The dimer synthon formed by the carboxyl group has been used to assemble a variety of supermolecules due to its bidentate character which increases the strength of the interaction. For example, terephthalic acid (8) [39] and iso-phthalic acid (9) [40] form one dimensional tapes. Trimesic acid (2) with its threefold molecular symmetry forms a two dimensional hydrogen bonded sheet [41] and adamantane-l,3,5,7-tetracarboxylic acid (10) with its tetrahedrally disposed carboxy functionality forms a diamondoid network (Fig. 9) [42]. 

Adamantanes. Tetramethyl adamantane-2,6-dione-l,3,5,7-tetracarboxylate heated with hydrazine hydrate and a soln. of Na in methanol 8 hrs. at 240-250° in a steel autoclave adamantane-l,3,5,7-tetracarboxylic acid. Y 80.5-93%. S. Landa and Z. Kamy ek, Coll. 24, 4004 (1959). 

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