N-Cyclohexylcarbodii
midomethyl Polystyrene Resin cross-linked with 1% DVB (50-100mesh) (1.4-1.6mmol/g) / 1-Benzyl-3-cyclohexy
lcarbodiimide Resin In recent years, the trend in synthetic organic chemistry has been to put special emphasis on harmonization with the environment and reaction efficiency. Much R&D is taking place to address these issues. Polymer-supported synthetic reagents and catalysts are drawing much attention due to the ease of recovery of the reagent after reaction. For this reason, many polymer-supported reagents and catalysts with excellent properties have been reported. One of the most common hypervalent iodine compounds, diacetoxyiodobenzene
, has been supported on polystyrene by Togo and co-workers, and they have reported the oxidation of various functional groups. For example, they have reported the oxidation of alcohols in the presence of this polymer-supported reagent and TEMPO.1) Ishikawa and co-workers have developed 1,3-dimethylimidazol
idinone supported on polystyrene. The derived 2-chloro-1,3-dimethy
limidazolidium, using oxalyl chloride, is used for the esterification as a polymer-supported dehydrating and condensation reagent.2) On the other hand, active research for development of the polymer-supported catalysts has also been carried out. Yao has developed a polyethylene glycol-bound Grubbs catalyst analog for olefin metathesis reactions.3) After the reaction, this catalyst was precipitated by the addition of diethyl ether as a poor solvent. It can be recovered and reused. Ishihara and his group have developed a polystyrene-bound 4-bis(triflyl)methyl
-2,3,5,6-tetrafluoro
benzene and demonstrated its applications as a solid super Brã¸nsted acid catalyst.4) This solid catalyst swells effectively in organic solvents, and shows excellent activity with various acid-catalyzed reactions. This catalyst has been used in esterification, Friedel-Crafts reaction, Michael addition, acetalization, Sakurai-Hosomi allylation and Mukaiyama aldol reaction. Its catalytic activity was superior even to that of Nafion, which is well known as a solid strong acid. After reaction, the solid catalyst was quantitatively recovered by simple filtration and reused. It was also packed in a syringe as a reaction column, and various acid-promoted reactions were performed to afford the desired products by passing a solution of reactants through the syringe.
N-Cyclohexylcarbodiimidomethyl Polystyrene Resin cross-linked with 1% DVB (50-100mesh) (1.4-1.6mmol/g) / 1-Benzyl-3-cyclohexylcarbodiimide Resin
In recent years, the trend in synthetic organic chemistry has been to put special emphasis on harmonization with the environment and reaction efficiency. Much R&D is taking place to address these issues. Polymer-supported synthetic reagents and catalysts are drawing much attention due to the ease of recovery of the reagent after reaction. For this reason, many polymer-supported reagents and catalysts with excellent properties have been reported.
One of the most common hypervalent iodine compounds, diacetoxyiodobenzene, has been supported on polystyrene by Togo and co-workers, and they have reported the oxidation of various functional groups. For example, they have reported the oxidation of alcohols in the presence of this polymer-supported reagent and TEMPO.1) Ishikawa and co-workers have developed 1,3-dimethylimidazolidinone supported on polystyrene. The derived 2-chloro-1,3-dimethylimidazolidium, using oxalyl chloride, is used for the esterification as a polymer-supported dehydrating and condensation reagent.2)
On the other hand, active research for development of the polymer-supported catalysts has also been carried out. Yao has developed a polyethylene glycol-bound Grubbs catalyst analog for olefin metathesis reactions.3) After the reaction, this catalyst was precipitated by the addition of diethyl ether as a poor solvent. It can be recovered and reused. Ishihara and his group have developed a polystyrene-bound 4-bis(triflyl)methyl-2,3,5,6-tetrafluorobenzene and demonstrated its applications as a solid super Brønsted acid catalyst.4) This solid catalyst swells effectively in organic solvents, and shows excellent activity with various acid-catalyzed reactions. This catalyst has been used in esterification, Friedel-Crafts reaction, Michael addition, acetalization, Sakurai-Hosomi allylation and Mukaiyama aldol reaction. Its catalytic activity was superior even to that of Nafion, which is well known as a solid strong acid. After reaction, the solid catalyst was quantitatively recovered by simple filtration and reused. It was also packed in a syringe as a reaction column, and various acid-promoted reactions were performed to afford the desired products by passing a solution of reactants through the syringe.
