Mesoporous poly-melamine-formaldehyde (mPMF) – a highly efficient catalyst for chemoselective acetalization of aldehydes

Abstract

A mesoporous poly-melamine-formaldehyde polymer with a high surface area, good porosity and a high density of amine and triazine functional groups was investigated as a highly efficient hydrogen-bonding catalyst. This porous organic polymer was found to be highly effective in catalyzing chemoselective acetalization of aldehydes, without the consumption of any dehydrating agents. The turnover frequency of mesoporous poly-melamineformaldehyde is hundreds of times higher than melamine monomer, and this high efficiency is due to the high density of aminal (-NH-CH 2 -NH-) groups and triazine rings in the polymer network, which provides an inherently powerful system with multiple hydrogen bonds. This unique characteristic imparts mesoporous poly-melamine-formaldehyde polymer with a very high activity as a heterogeneous organocatalyst. The polymer is also low cost, and easy to be synthesized and recycled. † Electronic supplementary information (ESI) available. See

Facile synthesis of mesoporous melamine-formaldehyde spheres for carbon dioxide capture

“…2B and b) and TEM ( Fig. More importantly, the similar results were also reported by Tan et al 30,31 In addition, the SEM images ( Fig. Moreover, to optimize the porosity and CO 2 adsorption characteristics, a series of MMFSs with different PFA/M molar ratios of 2.0 to 4.5 were synthesized.…”

“…It was revealed that high nitrogen (N) content and surface area can result in high uptake and selectivity simultaneously. [24][25][26][27][28][29][30][31][32] However, owing to the weak selfassembly ability of precursor components and the serious cross-linking of neighboring nanospheres during the hydrothermal process, the synthesis of mesoporous melamineformaldehyde spheres (MMFSs) through a simple, low-cost and environmentally friendly method is inherently nontrivial. More importantly, melamine resins can be produced in an industrial scale and widely used as a cross-linker in organic coatings and plastics.…”

Nanoporous Polymers: Bridging the Gap between Molecular and Solid Catalysts?

“… Organocatalytic reactions catalyzed by N‐containing Lewis bases within a) hyper‐cross‐linked high internal phase emulsion polymers,41 b) melamine‐formaldehyde resin,42 c) Tröger’s base CMP,44 d) Brønsted acids such as a HCP with carboxylic acid groups,32d and e) an aromatic framework containing amine and sulfonic acid moieties 45…”

Advances in Organic and Organic-Inorganic Hybrid Polymeric Supports for Catalytic Applications

“…A simple, green, and efficient strategy for the synthesis of benzoxazoles and benzothiazoles was developed [39] by using the mesoporous poly(melamine-formaldehyde) 50 [40][41][42] prepared starting from melamine and paraformaldehyde (Scheme 22). Polymer 50 acted as bifunctional catalyst and, under the optimized catalytic conditions, led to benzoxazoles and benzothiazoles with good and excellent yields (71%-99%) by reaction of substituted 2-aminophenols with benzaldehydes using dioxygen as oxidant.…”