Design and construction of polyaromatic group containing Cd(ii)-based coordination polymers for solvent-free Strecker-type cyanation of acetals

Abstract

In the present work, we have synthesized and characterized two novel Cd(II) coordination polymers, [Cd4(L1)4(DMF)6]n.3n(DMF) (1) and [Cd2(L2)2(DMF)3]n.2n(DMF) (2), and studied their catalytic application. They were synthesized via solvothermal reaction...

Two Zn(II)/Cd(II) Coordination Polymers as Recyclable Heterogeneous Catalysts for an Efficient Room-Temperature Synthesis of α-Aminonitriles via the Solvent-Free Strecker Reaction

“…35 (5-1H-imidazol-1-yl)isophthalic acid) required 10 wt % catalyst loading to complete the reaction in 18 h under solvent-free conditions. 35,38,39 Our previous work with a Zn(II) MOF, {[Zn 4 (μ 3 -OH) 2 (D-2,4-cbs) 2 (H 2 O) 4 ]•5H 2 O} n , required 5 mol % catalyst for a 92% conversion in 5 h using water as a solvent, 40 whereas Cd MOFs required 1−3 mol % loading for a full conversion. 36,37 For the lanthanide MOFs, the main drawback was the high reaction time.…”

“…Compared to the solvent-free, low catalytic loading, and room-temperature conditions used for 1a and 2a in this work, most of the heterogeneous catalysts for the Strecker reaction in the literature required the use of harsh conditions and high catalytic loadings (Table S5). − ,,, Selected examples from Table S5 are discussed further to elaborate these points. Certain In­(III)-based three-dimensional (3D) MOFs used for the reaction were found to be efficient at ambient temperature ranges with or without a solvent. ,− However, a Zr­(IV) 3D MOF afforded 100% conversion with 0.1 mol % catalyst loading at 50 °C .…”

“…On the other hand, an EOSIN-Y-modified Zr­(IV) MOF provided 96% conversion with 0.3 mmol catalyst loading in 24 h using methanol as the solvent . Among the Zn-based MOFs reported by others, {[Zn­(L)]·2DMF·2H 2 O} n and {[(CH 3 ) 2 NH 2 ]­[Zn 2 (L)­(H 2 O)­(PO 4 )]·2DMF} n (H 2 L = (5-1 H -imidazol-1-yl)­isophthalic acid) required 10 wt % catalyst loading to complete the reaction in 18 h under solvent-free conditions. ,, Our previous work with a Zn­(II) MOF, {[Zn 4 (μ 3 -OH) 2 (D-2,4-cbs) 2 (H 2 O) 4 ]·5H 2 O} n , required 5 mol % catalyst for a 92% conversion in 5 h using water as a solvent, whereas Cd MOFs required 1–3 mol % loading for a full conversion. , For the lanthanide MOFs, the main drawback was the high reaction time. − For example, the Sc­(III) MOF catalysts required less catalytic loadings, but the reaction time was up to 96 h. − Therefore, an overall analysis of the literature reports suggests that the present work has provided simple yet effective CPs to overcome the above-mentioned issues of high catalytic loading, drastic reaction conditions, and prolonged reaction time.…”

“…In view of this finding, metal complexes and metal oxides were tried as heterogeneous catalysts with easy separation and recyclability . Thus far, mostly indium (In)- and zirconium (Zr)-based MOFs/CPs were used as heterogeneous catalysts for the Strecker reaction in solvents, such as toluene, dichloromethane, and chloroform. − On the other hand, the d 10 metal-based MOFs/CPs have not been explored much. − Furthermore, no systematic study was conducted to evaluate the effect of UMCs on product yield. The preference for d 10 metal congeners, such as Zn­(II) and Cd­(II), lies in the fact that the variability in the coordination numbers in these two metal ions is a valuable tool for assessing the value of UMCs in such Lewis acid catalysis.…”

Polyaromatic Group Embedded Cd(II)-Coordination Polymers for Microwave-Assisted Solvent-Free Strecker-Type Cyanation of Acetals

“…Presently, several Lewis acid based homogenous catalysts, e.g., ZnI 2 , MgI 2 etherate, SnCl 2 , BiBr 3 , TiCl 4 , etc. [ 25 , 26 , 27 , 28 ], as well as a few heterogenous coordination polymers [ 29 ], have been reported. However, they suffer from various limitations, such as the need of anhydrous conditions, high catalyst loading and inability for recycling.…”