Topotactic Synthesis of Phosphabenzene‐Functionalized Porous Organic Polymers: Efficient Ligands in CO₂Conversion

Abstract

Progress toward the preparation of porous organic polymers (POPs) with task‐specific functionalities has been exceedingly slow—especially where polymers containing low‐oxidation phosphorus in the structure are concerned. A two‐step topotactic pathway for the preparation of phosphabenzene‐based POPs (Phos‐POPs) under metal‐free conditions is reported, without the use of unstable phosphorus‐based monomers. The synthetic route allows additional functionalities to be introduced into the porous polymer framework with ease. As an example, partially fluorinated Phos‐POPs (F‐Phos‐POPs) were obtained with a surface area of up to 591 m2 g−1. After coordination with Ru species, a Ru/F‐Phos‐POPs catalyst exhibited high catalytic efficiency in the formylation of amines (turnover frequency up to 204 h−1) using a CO2/H2 mixture, in comparison with the non‐fluorinated analogue (43 h−1) and a Au/TiO2 heterogeneous catalysts reported previously (<44 h−1). This work describes a practical method for synthesis of porous organic phosphorus‐based polymers with applications in transition‐metal‐based heterogeneous catalysis.

Conjugated Boron Porous Polymers Having Strong p−π* Conjugation for Amine Sensing and Absorption

“…Organic porous polymers (OPPs) are a class of emerging functional materials in the applications of gas storage/separation, heterogeneous catalysis, energy storage, sensors, and optoelectronics. − Conjugated porous polymers (CPPs), a subspecies of OPPs containing a π-conjugated backbone, have attracted significant attention recently . The functionalities of the CPPs are strongly dictated by chemical and electronic structures of their molecular building blocks. − With the development of CPPs, diverse and more complex building blocks have been explored for fulfilling specific functions. − For example, carbon (C), boron (B), and silicon (Si) containing tetrahedral building blocks have been introduced in CPPs to increase the surface areas of the materials. − While nitrogen (N) containing complex building blocks have been introduced in CPPs to enhance CO 2 absorption, − phosphorus (P) containing building blocks have been introduced to enhance catalytic performance of the materials. − Recently, B containing diverse building blocks have been introduced in CPPs to improve the sensing properties toward fluoride/cyanide anions and to modify the work function of the materials. − Although these diverse building blocks enrich the functionalities of CPPs, they also require very different reaction conditions, in which significant synthetic optimizations are generally required. Therefore, we envisioned that simple and commercially available building blocks are more appealing for considerably streamlining the synthesis of CPPs.…”

Solvent-Assisted Ruthenium Complex Catalyzes Hydrogenation and the Reductive Amination of Carbon Dioxide

“…Much effort has been devoted to developing new catalytic routes for the upgrading of renewable biomass and its derivatives to high-value chemicals and biofuels. , For example, levulinic acid (LA) and alkyl levulinates (e.g., methyl levulinate, ML) are important biomass-derived platform compounds, which can be obtained directly from lignocellulosic biomass in good yield by an easy separation procedure. − In addition, γ-valerolactone (GVL), reckoned as an energy substance and a key component in biorefinery systems, finds its applications in plenty of scenarios such as an intermediate for organic synthesis, a green solvent, a liquid fuel, a perfume, a food additive, and so forth. , In contrast, carbon dioxide (CO 2 ) is one of the main culprits of the greenhouse effect, which resulted in global warming and serious environmental problems. However, CO 2 is also a renewable source of carbon and has the advantage of being abundant, economic and nontoxic, which has attracted increasing interest in the chemical transformation of CO 2 . − In recent years, great efforts were made for the conversion of CO 2 into value-added chemicals, including cyclic carbonates, , formic acid, methanol, and amides, among others. − …”

Highly Efficient Heterogeneous Pd@POPs Catalyst for the N-Formylation of Amine and CO2

“…Additionally, the utilization of CO 2 as a carbon source for fine chemical synthesis can contribute to the reduction of CO 2 in the atmosphere [1][2][3]. Great efforts have been made by researchers for the conversion of CO 2 into value-added chemicals, such as formic acid [4,5], cyclic carbonates [6][7][8], and formamides [9]. Formamides are often used as intermediates for the synthesis of fine chemicals [10,11], Vilsmeier-Haack reaction, and solvents [12,13], and their production is one of the potential ways for the fixation of CO 2 .…”