10.1021/acs.joc.0c00882
The study presents an organocatalytic cascade reaction for synthesizing spirocyclic benzothiophenones with multiple stereocenters. The key chemicals involved are 2-alkylidene benzo[b]thiophenone derivatives acting as Michael acceptors and enones as donors. The reaction is catalyzed by a primary amine derived from cinchonidine, with 4-nitrobenzoic acid used as an additive. The process efficiently produces spirobenzothiophenonic cyclohexane derivatives with high yields (88-96%), enantioselectivities (85-97% ee), and diastereoselectivities (approximately 14/2/1). The synthesized compounds, containing three stereocenters, are valuable for their potential applications in medicinal chemistry due to their interesting physiochemical properties and biological activities. The study also explores the scope and limitations of the method, demonstrating its applicability with various enones and benzothiophenone derivatives, and showcases the potential for further transformations of the spirocompounds.
10.1016/j.poly.2009.06.056
The research investigates the formation of supramolecular dimers in copper(II) complexes through hydrogen bonding and their impact on magnetic properties. The study focuses on three copper(II) complexes: [Cu(3-O2Nbz)2(nia)(H2O)2] (1), [Cu(4O2Nbz)2(nia)2(H2O)2] (2), and [Cu(4-O2Nbz)2(nia)2]?(4-O2NbzH)2 (3), where 3-O2Nbz and 4-O2Nbz represent 3-nitrobenzoate and 4-nitrobenzoate anions, respectively, and nia represents nicotinamide. These chemicals play crucial roles in the formation of the complexes. The research involves the synthesis of these complexes using copper(II) acetate, nicotinamide, and either 3-nitrobenzoic acid or 4-nitrobenzoic acid. The structures of the complexes were determined through X-ray crystallography, revealing that complex (1) forms supramolecular dimers with strong hydrogen bonds between equatorially coordinated water molecules and uncoordinated carboxylate oxygen atoms, leading to antiferromagnetic interactions. The study provides experimental evidence that hydrogen bonds extended through carboxylate bridges can serve as pathways for spin–spin interactions, as demonstrated by the magnetic properties and EPR spectra of the complexes.
Xn
