1-adamantyl moiety

Polymers conjugated with 1-adamantyl moieties as lipophilic pendent groups can be utilized to design nanoparticulate dmg delivery systems. Polymer (1) in Fig. 26, which is synthesized by homopolymerization of ethyladamantyl malolactonate, can be employed as highly hydrophobic blocks to construct... 

Moine, L., Cammas, S., Amiel, C., Guerin, R, and SebUle, B. Polymers of malic acid conjugated with the 1-adamantyl moiety as lipophilic pendant group. Polymer 1997,38 3121-3127. 

Examples of this extreme stereoselectivity and specificity have been found by Scheffer and Trotter in crystals of a-adamantyl p-chloroacetophenone (86b), also [282], Figure 49 shows ORTEP-like drawings of the conformations in the dimorph plate and dimorph needle crystals of 86b as obtained upon recrystallization from different solvents. A major difference between the two is the cant of the aryl ring (and the carbonyl group) with respect to the adamantyl moiety. 

The enhanced efficacy of known drugs resulting from the introduction of an adamantyl moiety 344) is exemplified by the replacement of the butyl group of N-p-tolysulfonyl N-n-butylurea (106) by 1-adamantyl which results in a 15 fold increase in the hypoglycemic activity of the drug 345). On the... 

A large negative AH and a near zero AS were found for the complex. This result would suggest that inclusion of the adamantyl moiety in (3 - CD is an enthalpy-driven process and that Ka decreases when the temperature increases. 

Another reported synthesis of symmetrical spiro-1,3-dithietanes 163a-d substituted with an adamantyl moiety is based on the [2+2] cycloaddition of two molecules of variously substituted adamantane-2-thiones <1997BCJ509>. With methanesulfonic acid as an acidic catalyst, the reaction provided 1,3-dithietanes 163a-d in high yields at ambient temperature. A similar reaction was performed with phosphorus pentachloride as the catalyst (Equation 22 Table 8) <2002AXCo231>. 

D. Bera, P. Bandyopadhyay, S. Ghosh, S. Banerjee, Gas transport properties of aromatic polyamides containing adamantyl moiety, J. Membr. Sci. 453 (2014) 175-191. 

According to the solvophobic theory, the large round solvent cavity surrounding the hydrophobic adamantyl moiety should disappear upon inclusion by an appropriate host. Harrison and Eftink " investigated the inclusion thermodynamics of adamantanecarboxylate with )8-CD (Scheme 5) as a model system for examining the hydrophobic effect. Indeed, a linear correlation of AG° with y was observed for the 1 1 complexation of adamantanecarboxylate with /S-CD and also for the complexation of several other guests with CDs. ... 

For controlling the thermosensitivities of LCST polymers, PNIPAM copolymers with hydrophobic moieties have been prepared and their formations of complexes with CDs as host molecules have been investigated. The LCST of unmodified PNIPAM in water is generally insensitive to CDs. Ritter et al. first reported control of the LCST of a PNIPAM bearing adamantyl moieties 1 by the addition of Me2-P-CD (Figure 5.5). An aqueous solution of polymer 1 showed an LCST of 17 C this temperature was significantly lower than that of typical PNIPAM copolymers due to the hydrophobicity of the incorporated adamantyl moieties. 

Computational studies have provided a valuable working hypothesis for the Z-selectivity exhibited by cyclometalated catalyst 6 [31, 71, 72], In contrast to the bottom-bound metallacycles observed with previous generaticMis of ruthenium metathesis catalysts (cf. Sect. 2.1), it is proposed that ruthenacycles derived from 4 and 6 adopt a side-bound conformation (7a). The ratimiale for the preferential formation of side-bound ruthenacycles is twofold (Fig. 1) first, there are significant steric interactions present between the developing metaUacylobutane and the adamantyl moiety in the bottom-bound conformation (7b) that are alleviated in the side-bound conformation. Moreover, the bottom-bound conformation is destabilized as it requires back-donation from the same ruthenium d-orbital that is back-donating into the NHC this competition is alleviated in the side-bound conformation, as two separate metal d-orbitals are now available for back-donation into both the NHC and alkylidene carbon p-orbitals (Fig. 1) [71]. 

When aqueous solutions of two biopolymers, one carrying CD hosts and other carrying adamantyl moieties are combined, it may happen that this mixture will begin to associate... 

Since 39a is a homotetrameric protein with four identical biotin-binding sites, it can bind four equivalents of 40. It was observed that only two of the linkers, i.e. four adamantyl moieties bind four neighboring p-CD cavities of the p-CD SAM. Therefore it may be expected that the multivalency effect will make the binding of the complex 39a (40)4 to the P-CD SAM much stronger than the binding of 38. 

The first nitrile ylide stable enough to be isolated (i.e., 1) has been prepared by the carbene/nitrile method (1). For this dipole, the anionic component is stabilized by electron delocalization and the nitrilium component by the steric bulk of the adamantyl group to such an effect that it has a melting point of 230 °C. The X-ray structure showed that the nitrile ylide moiety is close to linear and much like the resonance structure shown below. 

---