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Eight new amorphous organic salts of folic acid (FA) were prepared by mechanochemistry. FA can prevent cardiovascular and neurological diseases. Mechanochemistry overcomes serious FA solubility issues avoiding the use of toxic solvents. Due to low FA solubility, therapeutic effects in supplements and drugs are not achieved. Current strategies to improve FA solubility include its derivatization by using complex synthetic procedures. Herein, a simple and green procedure, avoiding structural modifications, was designed using mechanochemistry. Biocompatible amine‐derivative coformers were strategically combined with FA to obtain salts with good physicochemical properties. New 1 : 1 and 1 : 2 amorphous FA salts offer 10 to 10,000 times better aqueous solubility and 10 to 100 times better octanol‐water partition coefficient values (Koctanol/water) than FA alone. Koctanol/water is considered as a surrogate of cell permeability. No toxic effects in normal human primary dermal fibroblasts were detected for the prepared FA salts. Our findings suggest that 1 : 2 FA salts of choline hydroxide and derivatives could be good candidates for future pharmaceutical/nutraceutical applications. [ABSTRACT FROM AUTHOR]

The coordination and catalytic properties of (1S,2S, 3S)-3hydroxycamphorsultam are studied by analyzing hydroxycamphorsultam-transition metal complexes. The ligand contains triethylammonium iron and hence cannot function as Lewis acid. Although the ligand cannot act as a catalyst to Diels-Alder reactions, dinuclear copper complexes function as oxidation catalysts. Also, the ligand acts as catalyst only when Cu...Cu length is more than 3 amstrongs.

Indazole is known as an important structural motif in medicinal chemistry and, recently, has also gained attention in other areas, such as materials chemistry, with many studies showing different potential applications for their regioisomers. Phosphonates are also a class of compounds with diverse applications, ranging from medicinal to material applications. Here we present the synthesis of 1H‐ and 2H‐indazolephosphonic acid derivatives substituted at C‐3, involving mono‐ or bisphosphonic acids, from their corresponding carboxylic acid and esters. These compounds were fully characterized, and their spectroscopic data were evaluated to identify and distinguish the structural scaffold of each phosphonic acid. Crystallization of [hydroxy(1‐methyl‐1H‐indazol‐3‐yl)methanediyl]bis(phosphonic acid) 7 afforded crystals suitable for single crystal X‐ray diffraction studies and its crystal structure details are also discussed. [ABSTRACT FROM AUTHOR]

Mechanochemistry has been assuming a major role in chemistry over the last years. Its potential in a wide variety of reactions is undeniable nowadays, contributing to sustainable chemistry and, at the same time, leading to lower reaction time, higher selectivity and novel reactivity. Herein we disclose new solid forms of pipemidic acid, an antibiotic against which bacteria have been developing resistance mechanisms, obtained by mechanochemistry. These forms are molecular salts with glycolic, oxalic and (R)- and (S)-camphorsulfonic acids, as well as a Cu(II) complex exhibiting a 1D hydrogen bonded network. To prove the importance of the technique, we present here also the rapid and high yielding mechanochemical synthesis of a previously reported Ag metal–organic framework with pipemidic acid. [ABSTRACT FROM AUTHOR]

An efficient new method for the arylation of aldehydes which used the dirhodium(II) catalysts and N-heterocyclic carbene (NHC) ligands is described. The study results highlight the saturated mono species (NHC-5)[Rh.sub.2][(OAc).sub.4]) as the most active catalyst and significant role of hydrogen bonding and solvent participation in the reaction mechanism.

The synthesis and characterization of a series of [[Co.sup.II](iminopyrrolyl)2] complexes in which the bidentate chelating ligands encompass increasing bulkiness is discussed. DFT calculations suggest that the square planar geometry is slightly more stable than the tetrahedral one due to a combination of steric and electronic reasons.

The reaction of titanium trisamidotriazacyclononane, ((Ti-(N(Ph)SiMe2)3tacn) with C60 led to the synthesis of (Ti(N(Ph)SiMe2)2tacn)C60 in high yield. Treatment of (Ti(N(Ph)SiMe2)2tacn)C60 with PhCH2Br led to the formation of (Ti(N(Ph)SiMe2)3tacn)Br and the radical PhCH2C60.

Research has been conducted on Li, Ti(III), and Ti(IV) trisamidotriazocyclononane complexes. The preparation of these complexes and their lithium and sodium derivatives is described.

Hydrogen bonds (HBs) play a key role in the supramolecular arrangement of crystalline solids and, although they have been extensively studied, the influence of their strength and geometry on crystal packing remains poorly understood. Here we describe the crystal structures of two novel protic gabapentin (GBP) pharmaceutical salts prepared with the coformers methanesulfonic acid (GBP:METHA) and ethanesulfonic acid (GBP:ETHA). This study encompasses experimental and computational electronic structure analyses of 1H NMR chemical shifts (CSs), upon in silico HB cleavage. GBP:METHA and GBP:ETHA crystal packing comprise two main structural domains: an ionic layer (characterized by the presence of charge‐assisted +NHGBP⋯O−METHA/ETHA HB interactions) and a neutral layer generated in a different way for each salt, mainly due to the presence of bifurcated HB interactions. A comprehensive study of HB networks is presented for GBP:METHA, by isolating molecular fragments involved in distinct HB types (NH⋯O, OH⋯O, and CH⋯O) obtained from in silico disassembling of an optimized three‐dimensional packing structure. Formation of HB leads to calculated 1H NMR CS changes from 0.4 to ~5.8 ppm. This study further attempts to assess how 1H NMR CS of protons engaged in certain HB are affected when other nearby HB, involving bifurcated or geminal/vicinal hydrogen atoms, are removed. [ABSTRACT FROM AUTHOR]

Abstract: The preparation and characterization of a whole family of hydrated ionic co‐crystals formed by both enantiopure l‐proline and racemic dl‐proline with LiX (X=Cl, Br, I) are reported. The chiral preference of the lithium cation for homochiral coordination, both in the formation of crystalline conglomerates (with Cl and Br) and racemates (with Cl and I), in which molecules of opposite chirality are confined to distinct crystal layers, is discussed. Dehydration processes for all hydrated crystals have also been investigated. [ABSTRACT FROM AUTHOR]

An alternative, efficient, and green synthetic strategy for the preparation of pharmaceutical ionic liquids using mechanochemistry (MechanoAPI-ILs) is reported. Six new API-ILs based on gabapentin and l-glutamic acid were successfully synthesized and characterized, demonstrating that mechanochemistry is a very promising synthetic strategy. Results compare both the new and the classical approach and clearly show the advantages of the new method. This new technique is faster, solvent free, reproducible, selective, and leads to higher yields. [ABSTRACT FROM AUTHOR]