Hisaho Hashimoto

New macromolecular ionophore: enantioselective membrane transport of racemic amino acid by poly[(1 → 6)-2,5-anhydro-3,4-di-O-methyl-d-glucitol]

Abstract The chiral recognition property of poly [(1 → 6)-2,5- anhydro -3,4- di -O- methyl- d -glucitol ] ( 2b ) towards racemic RCH(CO 2 CH 3 )NH + 3 ·X − (3·HX) has been studied using a transport system involving an aqueous source and receiving phases separated by a chloroform phase containing 2b . For HPF 6 , HClO 4 and HCl salts of 3a (R = Ph), the amount of 3a transported into the receiving phase decreased in the order of PF − 6 > ClO − 4 > Cl − , but the optical purities changed only slightly from 9.3 to 10.9%. The transport rates for aromatic guests, 3a and 3b (R = CH 2 Ph, were faster than those for aliphatic ones, 3c (R = CH(CH 3 ) 2 ) and 3d (CH 2 CH(CH 3 ) 2 ), using PF − 6 as the counterion. The optical purity was 10.9% for 3a as a maximum value and decreased in the order of 3a > 3c > 3b and 3d . The formationof a complex between 2b and 3a ·HX was confirmed by 1 H and 13 C n.m.r. spectral measurements.

Synthesis of poly(dibenzo-19-crown-6) via cyclopolymerization of diepoxide

SummarySynthesis and cyclopolymerization of 5,6;14,15-dibenzo- 1, 2; 18, 19-diepoxy- 4, 7, 10, 13, 16-pentaoxanonadeca- 5,14-diene (3) was carried out. The polymerization of 3 with tin tetrachloride and boron trifluoride etherate gave the polymers with lower molecular weight. Alternatively, triethylaluminium-water-acetylacetone (Vandenberg catalyst) was effective in preparing polymers of high molecular weight which were soluble in p-cresol and p-chlorophenol. The polymers were essentially composed of cyclic constitutional units corresponding to dibenzo-19-crown-6. The cation-binding ability of the polymer showed the highest selectivity for K+.

Synthesis and Cation-Binding Properties of (1→6)-2,5-Anhydro-D-glucitol with 3,4-Di-O-Pentyl and Decyl Groups by Cyclopolymerization of 1,2:5,6-Dianhydro-D-mannitols

Abstract The cyclopolymerizations of 1,2:5,6-dianhydro-3,4-di-O-pentyl-D-mannitol (1b) and 1,2:5,6-dianhydro-3,4-di-O-decyl-D-mannitol (1c) were carried out using BF3OEt2 and t-BuOK. All the resulting polymers consisted of cyclic constitutional units, i.e., the extent of cyclization was 100%. The polymer structures for the polymerization with t-BuOK were (1→6)-2,5-anhydro-3,4-di-O-pentyl-D-glucitol (2b) and (1→6)-2,5-anhydro-3,4-di-O-decyl-D-glucitol (2c), whereas those with BF3O-decyl2 comprised 2,5-anhydro-D-glucitols as major units along with other cyclic ones. These polymers were soluble in n-hexane, CHCl3, and THF, but insoluble in water, which differs from the amphiphilic solubility of (1→6)-2,5-anhydro-3,4-di-O-methyl-D-glucitol (2a). The cation-binding properties of 2b and 2c were examined using alkali-metal picrates in order to compare them with those of 2a. The extraction yields for each cation decreased in the order of 2c < 2b < 2a. Every polymer exhibited a similar cation-binding selectivity i...

Synthesis of Poly[(1→6)-2,5-Anhydro-D-Glucitol] by Cationic Cyclopolymerization of 3,4-Di-O-Allyl-1,2:5,6-Dianhydro-D-Mannitol

Abstract The cyclopolymerization of 3,4-di-O-allyl-1,2:5,6-dianhydro-D-mannitol (1d) using BF3·OEt2 produced poly[(1→6)-3,4-di-O-allyl-2,5-anhydro-D-glucitol] (2d). For the polymerization in CH2Cl2 at -10°C, the maximum yield and Mn were obtained as 58.9% and 4890, respectively. The specific rotations ([α]22546) of the obtained polymers were +34.0° ∼ +38.8° (c=1.0 in CHCl3). The deallylation of polymer 2d in acetic acid/ethanol/water using the Pd-C catalyst perfectly proceeded to form poly[(1→6)-2,5-anhydro-D-glucitol] (3). The specific rotations ([α]22546) of the resulting polymers were +17.1° ∼ +18.9° (c=1.0 in H2O). Polymer 2d was soluble in chloroform and tetrahydrofuran, but insoluble in water, whereas polymer 3 was soluble in water but insoluble in chloroform and tetrahydrofuran.

Cyclopolymerization of α,Ω-Diepoxide with Monoepoxy Comonomer. Synthesis and Cation-Binding Property of Copolymers with Dibenzo-19-Crown-6 Units

Abstract Cyclocopolymerizations of 5,6-benzo-l,2:9,10-diepoxy-4,7-dioxa-deca-5-ene (BDD) and monoepoxy comonomers, propylene oxide (PO), epichlorohydrin (ECH), and phenyl glycidyl ether (PGE), were carried out with SnCl4 to form gel-free copolymers with no residual epoxy groups. The copolymerization parameters were r, = 1.09 and r2 = 0.86 for BDD (M1)-PGE (M2). In addition, 5, 6:14,15-dibenzo-l,2:18,19-diepoxy-4,7,-10,13,16-pentaoxanonadeca-5,14-diene (DDP) with PO, ECH, or PGE were copolymerized with SnCl4 in CH2C12 and with KOH in DMSO to form copolymers with dibenzo-19-crown-6 units. Poly[(dibenzo-19-crown-6)-co-PO] and poly[(dibenzo-19-crown-6)-co-PGE] showed lower extracting yields for alkali-metal picrates than did the homopolymer of DDP, poly(dibenzo-19-crown-6). However, poly[(dibenzo-19-crown-6)-co-PGE] exhibited a higher selectivity for K+ than did the other polymers.

Synthesis of poly(hemispherand) via cyclopolymerization of diepoxide

SummaryCyclopolymerization of 2,6-bis[3-(4,5-epoxy-2-oxapentyl)-2-methoxy-5-methylphenyl]-4-methylanisole was carried out with cationic, anionic, and coordination catalysts. The polymers obtained with BF3·OEt2 or SnCl4 in dichloromethane and with t-BuOK in DMSO were soluble in benzene, chloroform, and THF. The mole fractions of the cyclic units in these polymers were from 0.65 to 0.75. The resulting poly(hemispherand) bound alkali metal cations and the selectivity was in the order of Rb+>K+>Cs+>Na+>Li+.