Recyclable Phase Transfer Catalyst Research Articles

Synthesis and characterization of a novel Fe3O4@SiO2/bipyridinium dichloride nanocomposite and its application as a magnetic and recyclable phase-transfer catalyst in the preparation of β-azidoalcohols, β-cyanohydrins, and β-acetoxy alcohols

One-pot preparation of β-azido alcohols, β-cyanohydrins, and β-acetoxy alcohols using Fe 3 O 4 @SiO 2 /BNC, as catalyst. β-Azidoalcohols, β-cyanohydrins, and β-acetoxy alcohols have been synthesized in the presence of a Fe 3 O 4 @SiO 2 /bipyridinium nanocomposite (Fe 3 O 4 @SiO 2 /BNC) as a novel magnetic and recyclable phase-transfer catalyst (PTC) in water. The catalyst was characterized with FT–IR, SEM, XRD, VSM, and TGA. This methodology offers several advantages, including easy work-up procedure, excellent regioselectivity, high yields, short reaction times, recyclable catalyst, easy separation of the catalyst through an external magnet and eco-friendly procedure.

Synthesis and characterization of a novel nano-Fe3O4-copoly[(styrene/acrylic acid)/grafted ethylene oxide and its application as a magnetic and recyclable phase-transfer catalyst in the preparation of β-azido alcohols and β-nitro alcohols

A facile method was developed for the synthesis of β-azido alcohols and β-nitro alcohols in the presence of a novel nano-Fe3O4-copoly[(styrene/acrylic acid)/grafted ethylene oxide (nano-Fe3O4-PS-Co-[PAA-g-PEG]) as a phase-transfer catalyst in water. The catalyst was characterized with IR, SEM, and TGA. This procedure offers several advantages, including excellent regioselectivity, high yields, short reaction times, a recyclable catalyst, easy separation of the catalyst through an external magnet, and easy workup .

ChemInform Abstract: Graphene Oxide as a Recyclable Phase Transfer Catalyst.

AbstractGraphene oxide (GO) shows competitive phase transfer catalytic properties in Michael additions to nitroalkenes compared to the established 18‐crown‐6 ether.

SYNTHESIS OF UNSATURATED ESTERS VIA HIGHLY EFFICIENT ESTERIFICATION CATALYZED BY POLYMER GRAFTED QUARTERNARY AMMONIUM SALTS AS TRIPHASE CATALYSTS

ABSTRACT A series of unsaturated esters were prepared via condensation of sodium carboxylates and alkenyl halide under the condition of macroporous polystyrene grafted quarternary ammonium salt as recyclable phase transfer catalyst, NaI as co-catalyst, Cu powder as inhibitor and H 2 O as solvent. Under optimal conditions, products yields are 78.2~ 96.0%. The catalyst can be convenient recycled and reutilized for about five times without losing its activity obviously. Keywords: green chemistry, triphase catalysis, polymer grafted quarternary ammonium salt, unsaturated ester INTRODUCTION Unsaturated esters are a kind of reactive plasticizer, which are important monomers in the manufacture of resin. At present, they continue to be in great demand in fields of aerospace, electronics and telecommunication. 1-2 Therefore, the development of new synthesis technology still holds great significance.In recent years, many efforts have been carried out on the synthesis of unsaturated ester. Among various approaches, the most preferred is condensation of alkali metal carboxylate with alkenyl halide. The original condensation were generally performed under high temperature and pressure, which was uneconomical and unsafe.

Graphene oxide as a recyclable phase transfer catalyst

We demonstrated a simple and green chemical method to obtain Michael adducts and their derivatives by using GO as a phase transfer catalyst with different kinds of bases in water and dichloromethane, and we also used GO multiple cycles almost without reduction in reaction yields.

Efficient synthesis of an enantiopure beta-lactam as an advanced precursor of thrombin and tryptase inhibitors.

A new and efficient synthesis of a beta-lactam that is an advanced precursor of inhibitors of thrombin and tryptase is reported. The reaction sequence is based on the use of an inexpensive enantiomerically pure starting material and is designed to allow access to both enantiomers of the target molecules by epimerization of a side-product obtained along the synthesis. An improved procedure for the epimerization step that takes advantage of the use of a polymer-supported and recyclable phase-transfer catalyst is described.

Synthesis of a poly(ethylene glycol)-supported tetrakis ammonium salt: a recyclable phase-transfer catalyst of improved catalytic efficiency

The immobilization of four quaternary ammonium groups on a poly(ethylene glycol) support provided an efficient and recyclable phase-transfer catalyst.

A Facile Preparation of Alkyl Azides from Alkyl Bromides and Sodium Azide Using 18-Crown-6 Ether Doped Clay

A high yield synthesis of alkyl azides is described from readily accessible alkyl bromides and sodium azide using a recyclable phase transfer catalyst, 18-crown-6 ether impregnated clay.