Convenient One‐Pot Procedures for the Synthesis of 2,2′:6′,2″‐Terpyridine

One‐pot reactions to produce 2,2′:6′,2″‐terpyridine (tpy) under mild conditions are described under both solventless and solvent‐assisted conditions. Tpy can be obtained in 32% yield in a simple one‐pot reaction, which can readily be scaled‐up to give large quantities of tpy. These new approaches are superior to those previously described because of the fast and efficient synthesis and purification of tpy.     

Efficient and Convenient Method for the Synthesis of N‐Arylhydrazones using a Palladium‐Catalyzed Bond‐Forming Reaction

A highly effective, convenient, and reproducible industrial process for palladium‐catalyzed carbon–nitrogen cross coupling has been developed and applied on a large scale. Thus various functionalized N‐arylhydrazones have been easily prepared and well characterized by conventional spectroscopic methods.     

Synthesis of Tri- and Disalicylaldehydes and Their Chiral Schiff Base Compounds

A suitable procedure for convenient preparation of 1,3,5-tris(4-hydroxy-5-formylphenyl)benzene (6) was exploited via 5-bromosalicylaldehyde as starting reactant. Among the obtained products, compound 6, 4-methoxy-3-formylphenylboronic acid (9), 1,3,5-tris(4-methoxy-5-formylphenyl)benzene (10), and 4-methoxy-4′-hydroxyl-3,3′-diformyl-1,1′-diphenyl (11) had not been reported previously. Two new chiral Schiff base ligands, L1 and L2, were obtained from the tri- or disalicylaldehydes.     

Conformational Isomerism in Monomeric,Low‐Coordinate Group 12 Complexes Stabilized by a Naphthyl‐Substituted m‐Terphenyl Ligand

The synthesis and characterization of the first series of low‐coordinate bis(terphenyl) complexes of the Group 12 metals, [Zn(2,6‐Naph₂C₆H₃)₂] ( 1 ), [Cd(OEt₂)(2,6‐Naph₂C₆H₃)₂] ( 2 ) and [Hg(OEt₂)(2,6‐Naph₂C₆H₃)₂] ( 3 ) (Naph=1‐C₁₀H₇) are described. The naphthyl substituents of the terphenyl ligands confer considerable steric bulk, and as a result of limited flexibility introduce multiple conformations to these unusual systems. In the solid state, complex 1 features a two‐coordinate Zn centre with the ligands oriented in a syn/anti conformation, whereas the three‐coordinate distorted T‐shaped complexes 2 and 3 feature the ligands in the syn/syn configurations. The results of DFT calculations are in good agreement with the solid‐state configurations for these complexes and support the spectroscopic measurements, which indicate several conformers in solution.     

Synthesis,Characterization and Biological Evaluation of Two Silver(I) trans‐Cinnamate Complexes as Urease Inhibitors

Two new silver(I) trans‐cinnamates, namely [Ag(2‐cca)(H₂O)]₂ ( 1 ) and [Ag(4‐cca)]_n ( 2 ) (2‐ccaH = 2‐chlorocinnamic acid and 4‐ccaH = 4‐chlorocinnamic acid), were synthesized and structurally characterized. Single crystal X‐ray studies reveal that each silver(I) atom in 1 is two‐coordinate by a 2‐chlorocinnamate ligand and one water molecule to afford a discrete centrosymmetric dimer with the ligand‐unsupported Ag···Ag interactions (3.218(4) Å), while a pair of symmetry‐related silver(I) atoms in 2 are clamped by two μ₂‐η¹:η¹ 4‐chlorocinnamate ligands to yield a binuclear silver(I) moiety incorporating a ligand‐supported Ag···Ag interaction (2.819(5) Å). Both complexes 1 and 2 show potent urease inhibitory activities with the respective IC₅₀ values of 0.66 and 1.10 μM.     

A General and Highly Selective Palladium‐Catalyzed Hydroamidation of 1,3‐Diynes

A chemo‐, regio‐, and stereoselective mono‐hydroamidation of (un)symmetrical 1,3‐diynes is described. Key for the success of this novel transformation is the utilization of an advanced palladium catalyst system with the specific ligand Neolephos. The synthetic value of this general approach to synthetically useful α‐alkynyl‐α, β‐unsaturated amides is showcased by diversification of several structurally complex molecules and marketed drugs. Control experiments and density‐functional theory (M06L‐SMD) computations also suggest the crucial role of the substrate in controlling the regioselectivity of unsymmetrical 1,3‐diynes.     

Catalytic Cleavage of Ether CO Bonds by Pincer Iridium Complexes

The development of efficient catalytic methods to cleave the relatively unreactive C? O bonds of ethers remains an important challenge in catalysis. Building on our group’s recent work, we report the dehydroaryloxylation of aryl alkyl ethers using pincer iridium catalysts. This method represents a rare fully atom‐economical method for ether C? O bond cleavage.