Remote substituent effects

These major trends in act can be qualitatively predicted using semi-empirical molecular orbital calculations. However, the methods fail to adequately predict some electronic effects, remote substituent effects and the influence of hydrogen bonding. Higher level ah initio or DFT calculations provide a better indication of trends in these circumstances. 

In order to activate remote substituent effects in cycloaromatization reactions, two orthogonal re-systems need to find a way to communicate. At first glance, this task... 

Stratakis, M., Sofikiti, N., Baskakis, C. and Raptis, C. (2004). Dye-sensitized intrazeolite photooxygenation of 4-substituted cyclohexenes. Remote substituent effects in regioselectivity and diastereoselectivity. Tetrahedron Lett. 45, 5433-5436... 

The effect of remote substitutents on the complexing ability of crown ethers [256] towards t-butylammonium salts has been studied by Moore et al. (1977). The results (Table 52) show that electron-attracting substituents decrease the stability of the complex. The t-BuNHJ cation is even more sensitive to remote substituent effects than alkali-metal cations. This fact was attributed to the non-polar character of the alkyl group and to the different structure of the... 

A related comparison of remote substituent effects on acidities is provided by the data in Table 6-20. Here, the acidities of/ -substituted benzoic acids complexed to chromium tricarbonyl are related to the acidity of the parent compound. 

Remote and proximate substituent effects on trishomocyclopropenium ion formation in solvolysis have been studied by Coates and Fretz (1977). p-Nitrobenzoates having methyl and phenyl substituents at the 9- or 2-positions have been solvolyzed. The results are consistent with the presence of trishomocyclopropenium ions as intermediates and that cyclopropane participation dominates over unassisted solvolysis by large margins in all cases. Furthermore, the results show that small remote substituent effects are not necessarily inconsistent with predominant -participation. 

Host-guest complexation. 4. Remote substituent effects on macrocyclic polyether binding to metal and ammonium ions, S. S. Moore, T. L. Tarnowski, M. Newcome and D. J. Cram, J. Am. Chem. Soc., 1977, 99, 6398. 

A book by Laugh in [76] is a very valuable reference on the aqueous phase behavior of surfactants. It covers this vast area of science from the viewpoints of the role of phase science within physical science, physical chemistry (thermodynamics of immiscibility, phase diagrams, the phase rule, characteristic features of surfactant phase behavior, kinetic and mechanistic aspects of surfactant phase behavior, relative humidity), structures and properties of surfactant phases, molecular correlations (surfactant and nonsurfactant behavior in amphiphilic molecules, hydrophilicity, lipophilicity, proximate and remote substituent effects, influence of third components on aqueous surfactant phase behavior), the relationship of the physical science of surfactants to their utility, and the history of surfactant phase science. 

K. B. Wiberg and S. L. Schreiber, ]. Org. Chem., 53, 783 (1988). Barriers to Rotation Adjacent to Double Bonds. 5. Remote Substituent Effects on the syn/skew Energy Difference for 1-Butene. 

The sensitivity of the Claisen rearrangement to remote substituent effects has been examined using 2-adamantyl vinyl ethers and allyl 2-adamantylidene ethers a-EWG substituents favor formation of the iyn-isomer. 

Lau, S.Y.W. and Keay, B.A. (1999) Remote substituent effects on the enantiomeric excess of intramolecular asymmetric palladium-catalyzed polyene cyclizations. Synlett, 605-7. 

Remote) substituent effects in an asymmetric Mizoroki-Heck cyclization... 

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