Triethylamine chloromethylated polystyrene

Example of the synthesis of a positively charged cross-linked polystyrene containing covalently bound porphyrin 18 mg (0.0244 mmol) of the tetra-aminophenylporphyrin zinc(II) complex was dissolved in 50 mL DMF. 1 g of the cross-linked chloromethylated polystyrene and then after 30 min 0.5 mL of triethylamine were added. The mixture was heated while slowly stirring for 24 h at 80 °C. The isolated polymer was treated with DMF. The amount of polymer-bonded porphyrin was determined from these solutions taking the absorption at... 

The resin-bound fragment preparation starts with the chlorine displacement from the chloromethylene function on a chloromethylated polystyrene by the cesium salt of Z-L-Cys(Tr)-OH. The resulting benzyl ester is treated with Scm-Cl to form the active intermediate sulfenyl thiocarbonate which is allowed to react with 4-acyloxy-6-mercaptodibenzofuran, preferably in dichloromethane-hexafluoro-2-propanol, with or without catalytic triethylamine (eq 16). ... 

The resulting 6-(methylthio)hexanoic acid is easily separable by aqueous extraction or by filtration through silica gel and can be reoxidized to 1873 with sodium metaperiodate in 97% yield. Low temperature (—60 °C) NMR spectrometry has been used to examine the intermediates of this Swem process. The results indicate that any residual unoxidized alcohol is generated during Pummerer elimination of the alkoxysulfonium intermediate and can be minimized by prolonged exposure to triethylamine at —40 °C. Reaction of the potassium salt of 1873 with cross-linked chloromethyl polystyrene affords a polymer-bound reagent that quantitatively oxidizes bomeol to camphor when used in two-fold excess [1394]. 

In a systemic kinetic study of the reaction of various amines with chloromethylated polystyrene (CMPS), Kawabe and coworkers found the rate profiles to be significantly Influenced by the nature of amine and the reaction media They observed that some cases conformed to simple second order reaction rate laws, but slight variations in the reaction conditions produced either deceleration or acceleration as quaternization proceeded (Table I) The deceleration was observed in the reactions of bulky amines i.e., diethyl-amine or dibutylamine, in DMF, DMSO and dioxane. This rate retardation could be attributed to the steric hindrance imposed by the quaternized neighboring group. The nature of the solvent also played an important role in the quaternization process for instance, a normal second order reaction was observed between triethylamine and CMPS in DMF. In DMSO, a deceleration attributed to an electrostatic effect was observed. ... 

The most widely nsed method to construct polypeptides is the use of a polymeric substrate to achieve multiple reactions. The Merrifield polypeptide synthesis on a polymeric substrate (crosslinked polystyrene) as the solid phase, revolutionized the synthesis of sequential polypeptides. The initial attachment of a protected amino acid to chloromethyl group containing polystyrene is achieved with triethylamine followed by hydrolysis to give 679 (Scheme 2.338, Step A). After removal of the protecting group, coupling of... 

Polymers with pendant carbodiimide groups 27 are also synthesized from crossUnked polystyrene. In this synthetic route crossUnked polystyrene beads are chloromethylated and converted to the amines. Reaction with isopropyl isocyanate gives the corresponding ureas, which are treated with tosyl chloride and triethylamine to produce the crossUnked polycarbodiimides. This polymer is used in the polymer supported Moffatt oxidation of alcohols into aldehydes or ketones using benzene/DMSO. ... 

Preparation of Polymer Catalysts (I-VI). Crosslinked polystyrene beads with 1% divinylbenzene mesh size 200-400 (SXl) purchased from Bio-Rad Laboratories, Inc., were chloromethylated by the method of Pepper, Paisley, and Young(24). The resin contained 4.59 meq/g of chloromethyl groups according to the modified Volhard method.(25) The chloromethylated resin was allowed to swell in dioxane-ethanol and reacted with histamine pyridine or triethylamine was used as an acid captor. The reaction mixture... 

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