Synthesis and Structure of Spirocyclic Tetraethers Derived from [1,1′-Binaphthalene]-2,2′-diol and Pentaerythritol

Selective CO2 adsorption in water-stable alkaline-earth based metal–organic frameworks

Four novel metal–organic frameworks (MOFs) built from alkaline-earth metal ions and the flexible ligand tetrakis[4-(carboxyphenyl)oxamethyl]methane acid (H₄L) were synthesized. Among them, Ca-based MOFs have high stability under humidity conditions and show good CO₂ uptake.

Axially Chiral Dimeric Naphthalene and Naphthoquinone Metabolites, from Root Cultures of the West African Liana Triphyophyllum peltatum

Root cultures of the West African liana Triphyophyllum peltatum were initiated from stem explants of in vitro cultivated shoots. From these organ cultures, three new binaphthalenes, one binaphthoquinone, and two (bi)naphthalene glucosides were isolated, with substitution patterns related to those of the naphthylisoquinoline alkaloids, which are the "normal" main metabolites of T. peltatum. The structures of the diglucoside dioncoquinoside A (1) and of the axially chiral biaryls triphyoquinols A1 (3), A2 (4), and B (5), triphyoquinoside A (6), and triphyoquinone A (7) were elucidated by spectroscopic analysis (HRESIMS, 1D and 2D NMR) and by application of electronic circular dichroism (ECD) spectroscopy in combination with the exciton chirality method and quantum-chemical ECD calculations. The root cultures likewise produced the known alkaloids dioncophylline A (8), 5'-O-demethyldioncophylline A (9), dioncopeltine A (10), habropetaline A (11), and 5'-O-methyldioncophylline D (12a/b), the naphthalene glucoside plumbaside A (2), and the naphthoquinones plumbagin (13), droserone (14), and 8-hydroxydroserone (15).

Binaphthyl-based chiral bifunctional organocatalysts for water mediated asymmetric List–Lerner–Barbas aldol reactions

Binaphthyl-based organocatalysts were synthesized and successfully applied to the asymmetric List–Lerner–Barbas aldol reaction in water medium. These organocatalysts were found to be effective catalysts for the reactions of ketones with different aldehydes to give aldol products with higher yield and ee's.