## Introduction
### Results and Discussion  
Polymer-supported ammonium salt **2a** was obtained as previously reported [20c] by _N_-alkylation of cinchonidine (**6**) with the Merrifield resin (Fluka, polystyrene crosslinked with 1% divinylbenzene, 1.7 meq Cl/g resin) in refluxing toluene, and is included in this study for comparison. When the _N_-alkylation reaction was carried out on _O_-allyl cinchonidine [5a] using Merrifield resin the _O_-allylated polymer **2b** was obtained, whereas resin **2c** was prepared similarly to resin **2a**, but using quinine (**7**) instead of cinchonidine. Moreover, we also prepared in the same way the (_1R,2S_)-_N_-methylephreine (**8**)-supported resin **9**, which has been previously used in the PTC ethylation of \(\alpha\)-cyanotoluene giving rather low _ee_'s [24], although its use in the alkylation of glycinimides was never attempted. After the preparation of these Merrifield resin-derived chiral ammonium salts, we thought to explore the influence of the support in the performance of the polymeric ammonium salts as PTC catalysts. Thus, we prepare the _N_-tritylated polymer-supported cinchonidine **10a** by reaction of **6** with the corresponding polymer bound triphenylchloromethane (Fluka, 1% DVB, 1.1 mmol Cl/g resin), and also its _O_-allylated counterpart **10b**, similarly to **2b**. In addition, the cinchonidine **6** was _N_-anchored to chloromethylated 1-[4-(4-vinylphenoxy)butoxy]-4-vinylbenzene-crosslinked polystyrene (JandaJel\({}^{\rm TM}\)Cl, Aldrich, 2% crosslinking, 0.45-0.7 mmol Cl/g resin) and to Wang-Br resin (Novabiochem, 1% DVB, 100-200 mesh, 1.19 mmol Br/g resin) to afford polymeric ammonium salts **11** and **12**, respectively. Finally, polymer-supported cinchonidine **13a** was obtained by reaction of **6** with chloromethylated polyethylenecol-polystyrene copolymer (ArgoGelTM-Cl, Argonaut Technologies, 1% DVB, 0.4 mmol Cl/g resin), whereas its \(O\)-allylated analogue **13b** was prepared as above. After the preparation of all these supported ammonium salts from commercially available polymers, we thought of the synthesis of an anchored cinchonidinium-derived ammonium salt incorporating a 9-anthrylmethyl moiety, which has shown its efficiency as an enantioselectivity-increasing group in _Cinchona_-derived PTC catalysts [5,6]. Thus, we prepared the mercapto resin **15** by treatment of the Merrifield resin (**14**) with thiourea and subsequent hydrolysis (Scheme 1) [25]. This resin was deprotonated with sodium hydride and reacted with 9,10-dichloromethylanthracene [26] (2 equiv) and subsequently with cinchonidine (**6**), affording polymeric salt **16**. The incorporation of the alkaloid in all these obtained catalysts was demosntrated by the presence of new bands in the IR spectra attributable to the alkaloid structure, and also by the increase in the initial resin weight and also the elemental analysis, which also allowed the determination of the loading. Finally, we also obtained co-polymeric cinchonidine-derived ammonium salt **18** by _N_-alkylation of an acrylonitrile and cinchonidine co-polymer **17**[27]. Thus, a mixture of acrylonitrile and cinchonidine (9:1 molar ratio) and a catalytic amount of azabisisobutyronitrile (AIBN) was heated in degassed DMF at 90\({}^{\circ}\)C affording after precipitation the co-polymer **17** (Scheme 2), which reacted with 9-chloro-methylanthracene to give co-polymeric ammonium salt **18**. Polymers **2**, **9-13** as well as **16** and **18** were used as insoluble PTC catalysts (0.1 eq) in the model triphase benzylation reaction of glycine-derived _N_-(diphenylmethylene)glycine isopropyl ester **19**[28] with benzyl bromide in an organic solvent and using an aqueous base (Scheme 3). The isopropyl ester **19** was chosen, instead of the _tert_-butyl derivative usually employed in asymdue to preliminary experiments using polymeric ammonium salts such as **2a**, which showed higher _ee_'s and lower reaction times in the alkylation of this glycine derivative [20c].