1-{(E)-[4-(4-Hydroxyphenyl)butan-2-ylidene]amino}-3-phenylthiourea: crystal structure, Hirshfeld surface analysis and computational study

The title thiourea derivative, C17H19N3OS, adopts a U-shaped conformation with the dihedral angle between the terminal aromatic rings being 73.64 (5)°. The major twist in the molecule occurs about the ethane bond with the Ci—Ce—Ce—Cb torsion angle being −78.12 (18)°; i = imine, e = ethane and b = benzene. The configuration about the imine bond is E, the N-bound H atoms lie on opposite sides of the molecule and an intramolecular amine-N—H...N(imine) hydrogen bond is evident. In the molecular packing, hydroxyl-O—H...S(thione) and amine-N—H...O hydrogen bonding feature within a linear, supramolecular chain. The chains are connected into a layer in the ab plane by a combination of methylene-C—H...S(thione), methylene-C—H...O(hydroxyl), methyl-C—H...π(phenyl) and phenyl-C—H...π(hydroxybenzene) interactions. The layers stack without directional interactions between them. The analysis of the calculated Hirshfeld surface highlights the presence of weak methyl-C—H...O(hydroxyl) and H...H interactions in the inter-layer region. Computational chemistry indicates that dispersion energy is the major contributor to the overall stabilization of the molecular packing.

Organocatalytic Enantioselective aza-Friedel-Crafts Alkylation of β-Naphthols and Isatin-Derived Ketimines via Takemoto-Type Catalyst

An organocatalytic enantioselective Friedel-Crafts alkylation of β-naphthols with isatins has been developed. The process is catalyzed by a simple thiourea derivative to give enantioenriched 3-(naphthalen-1-yl)-3-hydroxy-2-oxindoles in excellent yields of 89–95%...

Stereodivergent Synthesis of Camphor-Derived Diamines and Their Application as Thiourea Organocatalysts

A series of 18 regio- and stereo-chemically diverse chiral non-racemic 1,2-, 1,3-, and 1,4-diamines have been synthesized from commercial (1S)-(+)-ketopinic acid and (1S)-(+)-10-camphorsulfonic acid. The structures of the diamines are all based on the d-(+)-camphor scaffold and feature isomeric diversity in terms of regioisomeric attachment of the primary and the tertiary amine function and the exo/endo-isomerism. Diamines were transformed into the corresponding noncovalent bifunctional thiourea organocatalysts, which have been evaluated for catalytic activity in the conjugative addition of 1,3-dicarbonyl nucleophiles (dimethyl malonate, acetylacetone, and dibenzoylmethane) to trans-β-nitrostyrene. The highest enantioselectivity was achieved in the reaction with acetylacetone as nucleophile using endo-1,3-diamine derived catalyst 52 (91.5:8.5 er). All new organocatalysts 48–63 have been fully characterized. The structures and the absolute configurations of eight intermediates and thiourea derivative 52 were also determined by X-ray diffraction.