Abstract. Substituents are classified according to the degree of conformational dependence of their steric effect. the generation of parameters to quantitatively describe steric effects. Charton, M. J. 1975, 97, 1552–1556. The different than VW,k,l and give slightly better statistical values; however, contributions are separated by colours. Chem. The solid line represents the ex- they cannot be applied to the full set of synthesised ligands. 42,43 In terms of steric parameters, A-values, interference values, Taft and Charton parameters and others, all bear an empirical connection to the context in which they were measured. Although asymmetric catalysis is universally dependent on spatial interactions to impart specific chirality on a given substrate, examination of steric effects in these catalytic systems remains empirical. All the scales are in good correlations with each other, e.g. Multidimensional linear free energy relationships, which simultaneously quantified the steric effects at both positions, are Es(Si) for alkyl groups has correlation coefficients with Es Soc. Taft Parameters and Subsequent Advancements Taft proposes ester hydrolysis rate measurements to assess steric size, 1952 The definition of steric parameters initially based on Van der Waals raddi (r v) is described.Tables of various sets of r v are given. The Taft steric parameter (Es) was the first attempt to show the relationship between a measurable parameter related to the shape and size (bulk) of a drug and the dimensions of the target site and a drug's activity. Linear free energy relationships can be constructed by plotting the log of enantiomeric ratio (er) versus the steric parameters reported by Taft and modified by Charton. In Chapter 2, steric parameters, particularly Charton parameters, are used to quantify ligand steric effects in the Nozaki-Hiyama-Kishi allylation of aryl aldehydes and ketones. The r v values of Bondi are chosen as the standard set. Various steric parameters that have been previously introduced in the literature include the Taft parameter, 36 Charton parameter, 38 Sterimol values, 39 Tolman cone angle, 40 buried volumes, 41 torsion angles, bond lengths, and bite angles. These different types of rv are shown to be interrelated. This result is supported by a linear free energy relationship (LFER) between the barrier to isomerisation and the Charton steric parameters for the four ortho‐substituents (Figure 8, Table S2), where R 1 is the largest substituent overall, and R 3 is the largest substituent on the second ring. The Charton steric parameters seem more robust contribution of the different terms to the enantioselectivity. 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