One-step assembly of a MacMillan catalyst-based phenolic-type polymer

We report herein a "bottom-up" approach for the one-step assembly of a MacMillan catalyst-based phenolic-type polymer (Mac-CP). The resulting self-supported polymeric organocatalyst possesses homogeneously distributed and highly concentrated catalytic sites. Furthermore, Mac-CP is soluble in CH₃CN but insoluble in hexane. This unique property can be used to employ the polymer as an efficient catalyst in homogeneous organocatalysis and heterogeneous recycling. As a result, Mac-CP possesses comparable catalytic activity and enantioselectivity to its homogeneous counterpart in the asymmetric Diels-Alder reaction (95% yield, 93% enantiomeric excess (ee) for endo and 92% ee for exo).

TMSOTf-mediated Kröhnke pyridine synthesis using HMDS as the nitrogen source under microwave irradiation

An efficient protocol for the preparation of pyridine skeletons has been successfully developed involving the TMSOTf/HMDS (trifluoromethanesulfonic acid/hexamethyldisilane) system for the intermolecular cyclization of chalcones under MW (microwave) irradiation conditions. This method provides a facile approach to synthesize 2,4,6-triaryl or 3-benzyl-2,4,6-triarylpyridines in good to excellent yields. Interestingly, the 2,6-diazabicyclo[2.2.2]oct-2-ene core was obtained by changing the acid additive to Sn(OTf)2, and the desired product was also confirmed using X-ray single-crystal diffraction analysis.

A TEMPO-Functionalized Ordered Mesoporous Polymer as a Highly Active and Reusable Organocatalyst

The properties of high stability, periodic porosity, and tunable nature of ordered mesoporous polymers make these materials ideal catalytic nanoreactors. However, their application in organocatalysis has been rarely explored. We report herein for the first time the incorporation of a versatile organocatalyst, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), into the pores of an FDU-type mesoporous polymer via a pore surface engineering strategy. The resulting FDU-15-TEMPO possesses a highly ordered mesoporous organic framework and enhanced stability, and shows excellent catalytic activity in the selective oxidation of alcohols and aerobic oxidative synthesis of 2-substituted benzoxazoles, benzimidazoles and benzothiazoles. Moreover, the catalyst can be easily recovered and reused for up to 7 consecutive cycles.

Sustainable Four-Component Annulation for the Synthesis of 2,3,4,6-Tetraarylpyridines

A one-pot, four-component annulation of 2,3,4,6-tetraarylpyridines from aromatic aldehydes, methyl ketones, diaryl ethanones, and ammonium acetate is described. The reaction features high functional group compatibility in air under solvent-free conditions without any additive and only water as the nontoxic byproduct, providing a strategy for the facile, economical, and eco-friendly construction of multiaryl-substituted pyridines from simple and readily available reactants.

Thiophene-embedded conjugated microporous polymers for photocatalysis

“Bottom-up” embedding of thiophene derivatives into CMPs for highly efficient heterogeneous photocatalysis is reported.

Conjugated porous polymers: incredibly versatile materials with far-reaching applications

This review discusses conjugated porous polymers and focuses on relating design principles and synthetic methods to key properties and applications such as (photo)catalysis, gas storage, chemical sensing, energy storage and environmental remediation.

Pyrrolidine-based chiral porous polymers for heterogeneous organocatalysis in water

The “bottom-up” reticulation of chiral pyrrolidine into POPs for heterogeneous organocatalysis in pure water.

Synthesis of aminopyridine-containing conjugated microporous polymers with excellent superhydrophobicity for oil/water separation

Aminopyridine-containing conjugated microporous polymer based membranes with excellent superhydrophobicity for continuous oil/water separation on a large scale.

High Gas Uptake and Selectivity in Hyper-Crosslinked Porous Polymers Knitted by Various Nitrogen-Containing Linkers

By introducing various N-containing compounds as efficient linkers, a series of hyper-crosslinked porous polymers with high surface areas and gas-uptake values were synthesized by using the Friedel-Crafts alkylation reaction. Structural characterization indicated the presence of nitrogen atoms, and gas-sorption experiments revealed that the high gas uptake benefitted from the high surface areas and the incorporation of N-containing linkers as Lewis basic sites. Among these porous polymers, HCP-4 had the highest H2 uptake of 9.29 mmol g-1 at 77 K and 0.1 MPa and the highest C2H2 uptake of 6.69 mmol g-1 at 273 K and 0.1 MPa, whereas HCP-3 showed the best CO2 uptake of 4.42 mmol g-1 at 273 K and 0.1 MPa. To understand better the important role played by nitrogen in these polymers, the isosteric heat of adsorption and adsorption selectivity of CO2 over N2 were calculated. The results showed that the triazine-based polymer HCP-1 had the highest CO2 over N2 selectivity of 75.4 at 295 K and 0.1 MPa, which makes it the most potential candidate for CO2 capture.

Poly(aryleneethynylene)s: Properties, Applications and Synthesis Through Alkyne Metathesis

Functional polymeric materials have seen their way into every facet of materials chemistry and engineering. In this review article, we focus on a promising class of polymers, poly(aryleneethynylene)s, by covering several of the numerous applications found thus far for these materials. Additionally, we survey the current synthetic strategies used to create these polymers, with a focus on the emerging technique of alkyne metathesis. An overview is presented of the most recent catalytic systems that support alkyne metathesis as well as the more useful alkyne metathesis reaction capable of synthesizing poly(aryleneethynylene)s.

A facile approach for the synthesis of hydroxyl-rich microporous organic networks for efficient CO2 capture and H2 storage

A new series of porous organic networks (PONs) with N-donor sites and free hydroxyl groups in the backbone have been synthesized under high vacuum sealed tube conditions. These PONs possess high BET surface area and showed excellent H₂ and CO₂ storage capacities.

The “bottom-up” construction of chiral porous organic polymers for heterogeneous asymmetric organocatalysis: MacMillan catalyst built-in nanoporous organic frameworks

MacMillan catalyst-embedded chiral porous organic polymers were synthesized via bottom-up strategy and used as efficient and recyclable heterogeneous organocatalysts for the asymmetric Diels–Alder reaction.

Bipyridyl palladium embedded porous organic polymer as highly efficient and reusable heterogeneous catalyst for Suzuki–Miyaura coupling reaction

Bipyridyl-palladium catalyst embedded porous organic polymers (Bpy-Pd-POP) was synthesized and used as highly effective and reusable heterogeneous catalyst for the Suzuki–Miyaura coupling reaction.

4-Dialkylaminopyridine modified magnetic nanoparticles: as an efficient nano-organocatalyst for one-pot synthesis of 2-amino-4H-chromene-3-carbonitrile derivatives in water

A new DMAP-based magnetic nano-organocatalyst was developed for efficient one-pot synthesis of 2-amino-4H-chromene-3-carbonitrile derivatives in water as a green solvent.

Synthesis of metalloporphyrin-based conjugated microporous polymer spheres directed by bipyridine-type ligands

Metalloporphyrin-based conjugated microporous polymer spheres were obtained via Sonagashira–Hagihara cross coupling reactions directed by bipyridine-type ligands.

Porous polymer catalysts with hierarchical structures

The hierarchically porous polymer catalysts with fast mass transfer provide great opportunities for designing highly efficient heterogeneous catalysts.

Conjugated microporous polymers: design, synthesis and application

Conjugated microporous polymers (CMPs) are a class of organic porous polymers that combine π-conjugated skeletons with permanent nanopores, in sharp contrast to other porous materials that are not π-conjugated and with conventional conjugated polymers that are nonporous. As an emerging material platform, CMPs offer a high flexibility for the molecular design of conjugated skeletons and nanopores. Various chemical reactions, building blocks and synthetic methods have been developed and a broad variety of CMPs with different structures and specific properties have been synthesized, driving the rapid growth of the field. CMPs are unique in that they allow the complementary utilization of π-conjugated skeletons and nanopores for functional exploration; they have shown great potential for challenging energy and environmental issues, as exemplified by their excellent performance in gas adsorption, heterogeneous catalysis, light emitting, light harvesting and electrical energy storage. This review describes the molecular design principles of CMPs, advancements in synthetic and structural studies and the frontiers of functional exploration and potential applications.

Organocatalysis: Key Trends in Green Synthetic Chemistry, Challenges, Scope towards Heterogenization, and Importance from Research and Industrial Point of View

This paper purports to review catalysis, particularly the organocatalysis and its origin, key trends, challenges, examples, scope, and importance. The definition of organocatalyst corresponds to a low molecular weight organic molecule which in stoichiometric amounts catalyzes a chemical reaction. In this review, the use of the term heterogenized organocatalyst will be exclusively confined to a catalytic system containing an organic molecule immobilized onto some sort of support material and is responsible for accelerating a chemical reaction. Firstly, a brief description of the field is provided putting it in a green and sustainable perspective of chemistry. Next, research findings on the use of organocatalysts on various inorganic supports including nano(porous)materials, nanoparticles, silica, and zeolite/zeolitic materials are scrutinized in brief. Then future scope, research directions, and academic and industrial applications will be outlined. A succinct account will summarize some of the research and developments in the field. This review tries to bring many outstanding researches together and shows the vitality of the organocatalysis through several aspects.

Designing a yolk–shell type porous organic network using a phenyl modified template

A new strategy was developed to introduce gold nanoparticles into yolk–shell type porous organic networks under the assistance of a phenyl modified template.