One-Pot Synthesis of Bicyclic ortho-Aminocarbonitrile and Multisubstituted Cyclohexa-1,3-dienamine Derivatives

Dicyanopyridine derivatives: One-pot preparation, ACQ-to-AIE transformation, light-conversion quality and photostability

Low cost and strong fluorescence emission are two important guarantees for luminogens used as light conversion agents. By one-pot multicomponent approach and inexpensive starting materials, three dicyanopyridine (DP) derivatives named as DCP (2-amino-6-methoxy-4-phenylpyridine-3,5-dicarbonitrile), DCO (2-amino-6-methoxy-4-(4-methoxyphenyl) pyridine-3,5-dicarbonitrile) and DCC (2-amino-4-(4-cyanophenyl)-6-methoxypyridine-3,5-dicarbonitrile) were designed and synthesized. Meanwhile, the ACQ-to-AIE transformation was successfully realized by altering substituent groups rather than traditional rotor-stator theory. Based on crystal analysis and theoretical calculations, the ACQ-to-AIE transformation is attributed to the tunable stacking modes and intermolecular weak interactions. Owing to matched fluorescence emission, low lost, high yield, and AIE activity, DCC is used as light conversion agents and doped in EVA matrix. The light conversion quality confirms that DCC can not only convert ultraviolet light, but also significantly improve the transmittance of 25 %/40 % EVA, whose photosynthetic photon flux density at 400-500 nm and 600-700 nm increased to 30.67 %/30.21 % and 25.37 %/37.82 % of the blank film, respectively. After 20 h of UV irradiation (365 nm, 40 W), the fluorescence intensities of DCC films can maintain 92 % of the initial values, indicating good photostability in the doping films. This work not only provides an excellent and low-cost light conversion agent, but also has important significance for ACQ-to-AIE transformation of luminogens.

Design, fabrication and characterization of mesoporous yolk-shell nanocomposites as a sustainable heterogeneous nanocatalyst for synthesis of ortho-aminocarbonitrile tetrahydronaphthalenes

A new structure of mesoporous spherical nanocomposites was designed and easily prepared from the reaction between NiCuFe2O4 nanoparticles and mesoporous silica in three steps. The prepared multi-yolk@shell NiCuFe2O4@mSiO2 mesoporous sphere was characterized by using FT-IR, XRD, VSM, EDX, BET, FE-SEM and HR-TEM techniques. This unique mesoporous nanocomposite sphere as a heterogeneous nanocatalyst has demonstrated highly catalytic activity for the green synthesis of tetrahydronaphthalene derivatives in 92-98% yields at reaction times of 60-75 min. This process was carried out through multi-component reaction of the cyclic ketone, malononitrile and aromatic aldehyde under solvent-free conditions. Furthermore, the procedure was optimized on the basis of catalyst loading amounts, various solvents and temperature conditions. This novel methodology exposes obvious benefits such as; catalyst reusability, easy reaction procedure, simplicity of work-up, excellent product yields and short reaction times.

Fabrication and characterization of mesoporous yolk-shell nanocomposites as an effective reusable heterogeneous base catalyst for the synthesis of ortho-aminocarbonitrile tetrahydronaphthalenes

Mesoporous yolk-shell nanocomposites (MYSNs) were loaded with a mobile CaMg core inside the silica shell. CaMg@MYS nanocomposites have been effectively prepared inside the inner cavity of a novel structure that consists of hollow mesoporous silica spheres. Tetraethyl orthosilicate (TEOS) and an amount of cetyltrimethylammonium bromide (CTAB) are coated on the carbon spheres used as a hard template in the multi-step synthetic procedure. In this method, the target products were obtained in high to excellent yields between 87-96% and quick response times between 10-20 minutes under mild conditions. The CaMg@MYS catalyst shows promise as an efficient and reusable catalyst in multicomponent processes. The CaMg@MYS multi-yolk spheres compared to metal oxide nanostructures indicated both high catalytic performance and a significant factor as a novelty. To identify each product, FT-IR, ¹H NMR, and melting point techniques were applied. Also, in order to characterize the prepared catalysts, FT-IR, XRD, FE-SEM, EDS, elemental mapping, and HR-TEM techniques were applied.

Synthesis of cobalt tetra-2,3-pyridiniumporphyrazinato with sulfonic acid tags as an efficient catalyst and its application for the synthesis of bicyclic ortho-aminocarbonitriles, cyclohexa-1,3-dienamines and 2-amino-3-cyanopyridines

Cobalt tetra-2,3-pyridiniumporphyrazinato with sulfonic acid tag [Co(TPPASO3H)]Cl was produced and catalyzed the synthesis of ortho-aminocarbonitriles, cyclohexa-1,3-dienamines and 2-amino-3-cyanopyridines. The synthesis of 2-amino-3-cyanopyridines by using [Co(TPPASO3H)]Cl proceeded via a cooperative vinylogous anomeric based oxidation mechanism. [Co(TPPASO3H)]Cl can be recycled and reused six times with a marginal decreasing of its catalytic activity.