Pd@COF-QA: a phase transfer composite catalyst for aqueous Suzuki–Miyaura coupling reaction

Abstract

A COF-based phase transfer catalyst and its continuous flow-through reactor was prepared. The obtained Pd@COF-QA can highly promote the Suzuki–Miyaura coupling reaction in water under mild conditions even at gram scale level.

Homochiral Covalent Organic Frameworks for Asymmetric Catalysis

“…Some recent advances in achiral COF-based phase-transfer catalysis indicate that aqueous asymmetric catalysis promoted by HCCOF catalystss hould be viable. [18,42] Typically,C OFs are obtained as micro-or nanosized crystalline solids.T herefore, their handlinga nd processability are very difficult, which significantly limits their practical applicationsi n industry.Although some achiral COF-based self-supporting materials,s uch as membranes and aerogels, for catalysis have been reported very recently, [43] HCCOF-based materials of this type are still unprecedented. The shaping of HCCOFs,h owever, is extremelyi mportant to achieve cost-efficient, feasible, and easily popularized devices, and consequently,l arge-scale asymmetric catalysis.…”

“…Therefore, the synthesis of hydrophilic or phase‐transfer HCCOF catalysts is important and will lead to a variety of green chemical transformations. Some recent advances in achiral COF‐based phase‐transfer catalysis indicate that aqueous asymmetric catalysis promoted by HCCOF catalysts should be viable [18, 42] …”

“…For example, metal nanoparticles (M NPs) can be embedded in the HCCOF matrix by successive solution impregnation and metal reduction steps or a one‐pot in situ reducing approach (Scheme 1 a). [18] In doing so, the chiral confining effect of the HCCOF framework, the catalytic activity of the loaded catalysts, and so on can be logically integrated into the HCCOF platform. In comparison with conventional asymmetric catalytic systems, which are normally complicated, and various additives, such as cocatalysts, that often coexist, this concept of HCCOF‐based multifunctional integration might be more advanced and can hopefully provide an alternative method that will lead to enantioselective synthesis being economical, safe, eco‐friendly, energy saving, and resource saving.…”

An Ultrastable Crystalline Acylhydrazone‐Linked Covalent Organic Framework for Efficient Removal of Organic Micropollutants from Water

“…As a new type of robust linkages in the synthesis of COFs, the acylhydrazone-linked COFs by condensation between hydrazides and aldehydes show high crystallinity and improved chemical stability. Introduced by the pioneer work of Yaghi, [11] this type of COFs have attracted significant attention and shown great potentials in gas storage, [12] separation, [13,14] heterogeneous catalysis, [15][16][17][18][19] sensing, [5,[20][21][22] optoelectronics, [23] ion conduction, [24] and among others. [25][26][27][28][29][30] However, the low chemical stability for most of the acylhydrazone-linked COFs remains a major issue and prevents their wide applications.…”

Dual Nickel-/Palladium-Catalyzed Reductive Cross-Coupling Reactions between Two Phenol Derivatives

“…Next, 24 aryl tosylates were examined leading to cross-coupling products 23-46. A simple naphthyl tosylate led to 83% yield, and the introduction of electron-withdrawing or electron-donating groups on the naphthyl moiety only had a minor influence on the yield (23)(24)(25)(26). Notably, quinoline substrates were well-tolerated leading to good yields of the desired products (27)(28).…”