Reference

Surface active crown ethers

I. Macrocyclic polyethers of acetal type with long alkyl chain. Kuwamura, Tsunehiko; Kawachi, Terumasa (Fac. Eng., Gunma Univ., Kiryu, Japan). Yukagaku, 28(3), 195-8 (Japanese) 1979. CODEN: YKGKAM. ISSN: 0513-398X. DOCUMENT TYPE: Journal CA Section: 46 (Surface Active Agents and Detergents) Section cross-reference(s): 28 Acetals of higher aldehydes and diethylene glycol were treated with diethylene glycol ditosylate [7460-82-4] in the presence of tert-BuOK to prep. 2-alkyl-1,3,6,9,12,15,18-heptaoxacycloeicosanes stable in dil. alk. solns. The cyclic polyoxyethylenes had lower hydrophilicity than linear polyoxyethylenes. No significant differences were obsd. between the acetal crown ethers and polyoxyethylenes in surface properties, the surface tension above crit. micelle concns., and the mol. area on absorption at air-water interfaces. The acetal crown ethers catalyzed the reaction of BuBr [109-65-9] with KOPh [100-67-4], and the catalytic activity in benzene was high.

Substrate selectivity effects involving polymer-supported phase-transfer catalysts

MacKenzie, W. M.; Sherrington, D. C. (Dep. Pure Appl. Chem., Univ. Strathclyde, Glasgow G1 1XL, Scot.). Polymer, 22(4), 431-3 (English) 1981. CODEN: POLMAG. ISSN: 0032-3861. DOCUMENT TYPE: Journal CA Section: 35 (Synthetic High Polymers) Section cross-reference(s): 22 Substrate selectivity effects involving polymer-supported phase transfer catalysts were studied using R[O(CH2)2]3OMe (R = a polystyrene residue), R[O(CH2)2]30OPh, HO[(CH2)2O]3Me [112-35-6], and HO[(CH2)2O]30Ph [9004-78-8] as catalysts for the reactions of solid PhOK [100-67-4] with 1-bromobutane [109-65-9] and 1-bromooctane [111-83-1] in PhMe at 150°. In addn., polystyrene-bound N-benzylpyridinium bromide and N-benzyl-4-ethylpyridinium bromide [79094-67-0] were used to catalyze the reactions of aq. PhOK and 2-naphthoxide [135-19-3] with PhCH2Br [100-39-0] and 2-bromomethylnaphthalene [939-26-4] in PhMe. For the oligoether catalysts there was little difference in reactivity between bound and unbound species, and there was no effect of substrate size in changing from 1-bromobutane to 1-bromooctane. The difference in initial reaction rates of the 2 alkyl bromides was ~3 in the case of the oligoethers compared with ~1.5 and ~3 for their unbound analogs. The distribution of the alkyl halides between the bulk PhMe phase and the swollen R[O(CH2)2]3OMe was also examd. The supported pyridinium salt-catalyzed reactions were an order of magnitude slower than the unbound analog-catalyzed reactions, and the reactions were slower with more highly crosslinked polymer, indicating diffusional control by the support.