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The application of computational methods in enantioselective catalysis has evolved from the rationalization of the observed stereochemical outcome to their prediction and application to the design of chiral ligands. This Perspective provides an overview of the current methods used, ranging from atomistic modeling of the transition structures involved to correlation-based methods with particular emphasis placed on the Q2MM/CatVS method. Using three enantioselective palladium-catalyzed reactions, namely, the conjugate addition of arylboronic acids to enones, the enantioselective redox relay Heck reaction, and the Tsuji–Trost allylic amination as case studies, we argue that computational methods have become truly equal partners to experimental studies in that, in some cases, they are able to correct published stereochemical assignments. Finally, the consequences of this approach to data-driven methods are discussed. 

The synthesis of the title compound, C 13 H 21 NO 2 S, is reported here along with its crystal structure. This compound crystallizes with two molecules in the asymmetric unit. The sulfonamide functional group of this structure features S=O bond lengths ranging from 1.433 (3) to 1.439 (3) Å, S—C bond lengths of 1.777 (3) and 1.773 (4) Å, and S—N bond lengths of 1.622 (3) and 1.624 (3) Å. When viewing the molecules down the S—N bond, the isopropyl groups are gauche to the aromatic ring. On each molecule, two methyl hydrogen atoms of one isopropyl group are engaged in intramolecular C—H...O hydrogen bonds with a nearby sulfonamide oxygen atom. Intermolecular C—H...O hydrogen bonds and C—H...π interactions link molecules of the title compound in the solid state. 

Treatment of 2,4-dinitrophenol with sulfonyl chlorides in the presence of pyridine results in the formation of undesired pyridinium salts. In non-aqueous environments, the formation of the insoluble pyridinium salt greatly affects the formation of the desired product. A facile method of producing the desired sulfonate involves the use of an aqueous base with a water-miscible solvent. Herein, we present the optimization of methods for the formation of sulfonates and its application in the production of desired x-substituted 2,4-dinitrophenyl-4′-phenylbenzenesulfonates. This strategy is environmentally benign and supports a wide range of starting materials. Additionally, the intermolecular interactions of these sulfonate compounds were investigated using single-crystal x-ray diffraction data. 

The molecular structure of the title compound, C 11 H 15 NO 2 S, features a sulfonamide group with S=O bond lengths of 1.4357 (16) and 1.4349 (16) Å, an S—N bond length of 1.625 (2) Å, and an S—C bond length of 1.770 (2) Å. When viewing the molecule down the S—N bond, both N—C bonds of the pyrrolidine ring are oriented gauche to the S—C bond with torsion angles of −65.6 (2)° and 76.2 (2)°. The crystal structure features both intra- and intermolecular C—H...O hydrogen bonds, as well as intermolecular C—H...π and π–π interactions, leading to the formation of sheets parallel to the ac plane. 

The title compound, C 15 H 17 NO 2 S, was synthesized via a substitution reaction between 4-methylbenzylamine and p -toluenesulfonyl chloride. In the crystal, N—H...O hydrogen bonds link the molecules, forming ribbons running along the b -axis direction. One of the aromatic rings hosts two intermolecular C—H...π interactions that link these hydrogen-bonded ribbons into a three-dimensional network. 

The crystal structure of the title sulfonamide, C 10 H 15 NO 2 S, comprises two molecules in the asymmetric unit. The S=O bond lengths of the sulfonamide functional group range from 1.428 (2) to 1.441 (2) Å, with S—C bond lengths of 1.766 (3) Å (for both molecules in the asymmetric unit), and S—N bond lengths of 1.618 (2) and 1.622 (3) Å, respectively. When both molecules are viewed down the N—S bond, the propyl group is gauche to the toluene moiety. In the crystal structure, molecules of the title compound are arranged in an intricate three-dimensional network that is formed via intermolecular C—H...O and N—H...O hydrogen bonds. The crystal structure was refined from a crystal twinned by inversion. 

The syntheses and crystal structures of the two title compounds, C 11 H 10 O 3 ( I ) and C 17 H 14 BrNO 2 ( II ), both containing the bicyclo[2.2.2]octene ring system, are reported here [the structure of I has been reported previously: White & Goh (2014). Private Communication (refcode HOKRIK). CCDC, Cambridge, England]. The bond lengths and angles of the bicyclo[2.2.2]octene ring system are similar for both structures. The imide functional group of II features carbonyl C=O bond lengths of 1.209 (2) and 1.210 (2) Å, with C—N bond lengths of 1.393 (2) and 1.397 (2) Å. The five-membered imide ring is nearly planar, and it is positioned exo relative to the alkene bridgehead carbon atoms of the bicyclo[2.2.2]octene ring system. Non-covalent interactions present in the crystal structure of II include a number of C—H...O interactions. The extended structure of II also features C—H...O hydrogen bonds as well as C—H...π and lone pair–π interactions, which combine together to create supramolecular sheets.