A series of polymer-supported N-heterocyclic carbene silver complexes were prepared using a simple procedure via click chemistry. These complexes were tested as catalysts in the synthesis of propargylamines by the one-pot three-component coupling reaction of aldehydes, amines and alkynes (A(3)-coupling). The reaction was preceded smoothly to afford the corresponding products in good to excellent yields at room temperature under low catalyst loading of 0.1 mol%. Furthermore, the catalysts were stable and recoverable for six runs without a significant loss in their activity.
A series of new 4d-4f heterometallic coordination complexes based on 5-(4H-1,2,4-triazol-4-yl) benzene Eu (5) and Tb (6)] and [AgLn(L) 2 (H 2 O)]$H 2 O [Ln ¼ Er (7) and Yb (8)] were successfully synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR, elemental and thermogravimetric analyses. Complexes 1-3 consist of two-dimensional (2D) networks, which are further connected by hydrogen bonding and p-p interactions to give threedimensional (3D) frameworks. Complexes 4-6 display a 3D (4,6)-connected framework containing 2D heterometallic bilayers. Complexes 7 and 8 are 3-fold interpenetrated (3,4,6)-connected 3D frameworks. The results show that the reaction temperature and the lanthanide have great influence on the structure of the complexes. Luminescent measurements revealed that 2, 3, 5 and 6 exhibit the characteristic emission bands of the lanthanide in the visible region with lifetimes in the range of 0.24-1.81 ms and the strongest emissions are 5 D 0 / 7 F 2 for 2 and 5, and 5 D 4 / 7 F 5 transitions for 3 and 6.
Six new metal–organic coordination polymers [Mn(H3L)(ox)]·H2O (1), [Zn2(H2L)(pbdc)(μ2-OH)]·2H2O (2), [Co(H3L)(obea)]·3H2O (3), [Ni(H3L)(pbea)] (4),
[Co(H3L)(pbea)(H2O)2] (5), and [Co4(H2L)2(pbea)3] (6) were synthesized by reactions of the corresponding
metal salt with rigid tripodal ligand 1,3,5-tri(1H-imidazol-4-yl)benzene
(H3L) and different dicarboxylic acid of oxalic acid (H2ox), 1,4-benzenedicarboxylic acid (H2pbdc), 1,2-phenylenediacetic
acid (H2obea), 1,4-phenylenediacetic acid (H2pbea), respectively. The results of X-ray crystallographic analysis
indicate that 1 and 3 are two-dimensional
(2D) networks with 63-hcb topology, while 2 is (4,5)-connected three-dimensional (3D) net with Point
(Schläfli) symbol of (42·52·72)(42·53·74·8).
Complex 4 is a binodal (3,4)-connected 2D network with V
2
O
5
-type topology. Complexes 5 and 6 were obtained through controlling reaction temperature, 5 features a one-dimensional (1D) chain, whereas 6 is
an unprecedented tetra-nodal (3,4)-connected 3D net with Point (Schläfli)
symbol of (4·62·103)(4·62)(4·64·8)2 attributable to
the rich coordination modes of the ligands. The results of magnetic
measurements showed that there are antiferromagnetic interactions
in 1. Complex 2 exhibits intense light blue
emission in the solid state at room temperature, while 3 shows water vapor adsorption property.
An organocatalytic approach for the synthesis of isochroman derivatives via direct C(sp3)–H bond and N–H bond coupling is described. The C–N (amine or amide) and CN (imidate) products can be selectively achieved by controlling the amount of oxidants.
An efficient method for the preparation of isothiochromene derivatives through the palladium‐catalyzed intramolecular hydrothiolation reaction of halides and thiourea is reported. Two carbon–sulfur bonds are formed in this one‐pot palladium‐catalyzed cascade reaction. This new protocol is free from foul‐smelling thiols and operates under mild conditions to give isothiochromene derivatives in excellent yields and with excellent 6‐endo‐dig selectivity.
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