Aqua complex of iron(III) and 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydroxybenzenesulfonate: Structure and catalytic activity in Henry reaction

Hydrosoluble Complexes Bearing Tris(pyrazolyl)methane Sulfonate Ligand: Synthesis, Characterization and Catalytic Activity for Henry Reaction

“…The results show that the aromatic aldehydes with electrondonating substituents (OCH3 or CH3, Table 3, entries 1-4) exhibit a lower reactivity than those bearing electron-withdrawing groups (NO2, Br or Cl, Table 3, entries 7-12) due to the higher electrophilicity of the aldehyde in the latter case. In comparison to the scarce examples found in the literature for the catalytic nitroaldol reaction in water, using catalysts based on different metals (Table S3), the conversions obtained in this work are comparable, or better in some cases, taking into consideration the indicated reaction conditions such as temperature, amount of catalyst, and reaction time [43,44,[60][61][62][75][76][77][78][79][80].…”

An Efficient Synthesis of 1,2,4-Trisubstituted Imidazoles from Arylacetic Acids andN-Arylbenzamidines via Simultaneous C-H and N-H Bond Activation

“…α‐hydroxy carboxylic acid on dehydrogenation followed by decarboxylation offered aromatic aldehyde A . On the other hand, N−H activation, of N ‐arylbenzamidine led to its condensation with aromatic aldehyde A to form 2,4‐di‐azadiene which upon Michael addition, with CH 3 NO 2 produced ring annulated intermediate B . The 5‐exo‐trig cyclization of intermediate B resulted in formation of imidazole backbone which eventually on β‐hydride elimination offers desired 1,2,4‐trisubstituted imidazole 3 .…”

Interplay between Resonance‐Assisted Hydrogen Bonding and Coordination in Sulfo‐Functionalized Arylhydrazones of Active Methylene Compounds

“…Thus, if Fe III ions interact with AHAMC species that contain three‐centered RAHB (e.g., sodium 5‐chloro‐3‐[2‐(2,4‐dioxopentan‐3‐ylidene)hydrazinyl]‐2‐hydroxybenzenesulfonate, which is related to the NaHL 1–3 SAHAMCs), the Fe III –SAHAMC complexes can be formed directly even in an acidic medium 3g. m However, to achieve the coordination of SAHAMCs to other transition‐metal ions, deprotonating agents have to be used in most of the cases. Moreover, RAHB can be weakened by the interaction with alkali or alkali‐earth metal ions (see above).…”

“…3 In fact, they are easy to synthesize and modify,2, 4 and can form a wide range of coordination compounds2 and several types of intramolecular hydrogen bonding 3. 5 The AHAMCs with a sulfo substituent (SAHAMCs) are of particular interest because they possess a rich coordination chemistry,3c–j,m,q–s can form two‐ or three‐centered RAHBs depending on the position of the SO 3 − group (Scheme b), and are easy to handle owing to their stability and high solubility in polar solvents. Furthermore, their basic form is readily obtained in light of the easy deprotonation of the sulfonic group (SO 3 H) in the acidic form 3d,e…”