Mesoporous Ionically Tagged Cross-Linked Poly(vinyl imidazole)s as Novel and Reusable Catalysts for the Preparation of N-Heterocycle Spiropyrans

Abstract

Herein, two novel mesoporous cross-linked poly(vinyl imidazole)s with sulfonic acid tags, [PVI-SO3H]Cl (1) and [PVI-SO3H]FeCl4 (2), were prepared and characterized by a variety of techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy, elemental mapping, energy dispersive X-ray analysis, transmission electron microscopy, thermal gravimetry, derivative thermal gravimetry, and N2 adsorption–desorption isotherms (Brunauer–Emmett–Teller). In addition, magnetic properties of poly(vinyl imidazole) sulfonic acid iron(IV) chloride [PVI-SO3H]FeCl4 (2) as an ionically tagged magnetic polymer were investigated using a vibrating sample magnetometer. The presented polymers, [PVI-SO3H]Cl (1) and [PVI-SO3H]FeCl4 (2), were successfully applied as reusable and efficient catalysts for the preparation of N-heterocycle spiropyrans. The described catalysts were recycled and reused with a marginal decrease in their catalytic activities. The desired products were prepared under mild and green conditions. The structures of the obtained products were confirmed by various analysis techniques.

Application of [PVI-SO3H]NO3 as a novel polymeric nitrating agent with ionic tags in preparation of high-energetic materials

“…As can be seen from SEM micrographs, the morphology of reagent indicating a complete surface morphology change caused by adding of HNO 3 to [PVI-SO 3 H]Cl. 46 However, the shape of particles is cauliflower and nano-scales.…”

“…[35][36][37][38][39] In this regard, we have reported novel nitrating agents [Msim] At rst, poly(vinyl imidazole) (PVI) was synthesized according to the previously reported literature (Scheme 3). 44,45 In a 25 mL round-bottomed ask, a mixture of poly(vinyl imidazole) (PVI) (1.410 g) and chlorosulfonic acid (5 mmol, 0.335 mL) in dry CH 2 Cl 2 at 0 C was stirred for 2 h. 46 Then, nitric acid 100% (5 mmol, 0.20 mL) was added dropwise to [PVI-SO 3 H]Cl over a period of 5 minutes at room temperature. Aer this time, an orange powder appeared to give poly(vinyl imidazole) sulfonic acid nitrate [PVI-SO 3 H]NO 3 (Scheme 3).…”

Catalytic synthesis of new pyrazolo [3,4-b] pyridine via a cooperative vinylogous anomeric-based oxidation

“… Entry Catalyst (Mol %) (Time/min.) Yield (%) 1 FeCl 3 10 120 – 2 [PVI-SO 3 H]FeCl 4 82 10 mg 120 48 3 CF 3 SO 3 H 10 120 15 4 H 2 SO 4 10 120 42 5 [Py-SO 3 H]Cl 83 10 mg 120 36 6 Fe 3 O 4 10 mg 120 – 7 K 2 CO 3 10 120 – 8 SSA 84 , 85 10 mg 120 20 9 Et 3 N 10 120 – 10 NaOH 10 120 – 11 MIL-100(Cr)/NHEtN(CH 2 PO 3 H 2 ) 2 86 <...…”

Catalytic Application of a Novel Basic Alkane‐sulfonate Metal‐organic Frameworks in the Preparation of Pyrido[2,3‐d]pyrimidines via a Cooperative Vinylogous Anomeric‐based Oxidation

“…As shown in Table 2, [Zr-UiO-66-PDC-(CH 2 ) 4 -SO 3 ] is the best catalyst for the synthesis of (mono, bis, tris and tetrakis) pyrido [2,3-d]pyrimidine derivatives (entry 8, Table 2). [PVI-SO 3 H]Cl [50] 10 (mg) 120 52 6…”