Binaphthyl-based polymers

Optically active 1,1 -binaphthyl-based polymers incorporate chiral 1,17-binaphthyl units into the polymer backbone and possess stable main-chain... 

COPOLYMERS. ADJUSTMENT OF THE CONJUGATION OF THE BINAPHTHYL BASED POLYMERS [28a]... 

Chiral l,l -Binaphthyl-Based Helical Polymers as Nonlinear Optical Materials... 

Binaphthyl molecules (chiral 2,2/-dihydroxy-l,T-binaphthyl) have been studied by Hicks et al., who reported the first experimental observation of CD-SHG on surfaces.4,29,43 In this section, we investigate the nonlinear optical properties of a chiral 1,1-binaphthyl-based helical polymer. 

Bi-2-naphthols are among the most successful chiral ligands for several asymmetric catalysts. The synthesis of binaphthyl-based chiral polymers as rigid and sterically regular chiral polymers has recently been studied extensively [65-71]. Some recent devel-... 

Optically active l,l -binaphthols are among the most important chiral ligands of a variety of metal species. Binaphthol-aluminum complexes have been used as chiral Lewis acid catalysts. The l,T-binaphthyl-based chiral ligands owe their success in a variety of asymmetric reactions to the chiral cavity they create around the metal center [107,108]. In contrast with the wide use of these binaphthyls, the polymer-supported variety has been less popular. The optically active and sterically regular poly(l,l -bi-naphthyls) 96 have been prepared by nickel-catalyzed dehalogenating polycondensation of dibromide monomer 95 (Sch. 7) [109] and used to prepare the polybinaphthyl aluminum(III) catalyst 97 this had much greater catalytic activity than the corresponding monomeric catalyst when used in the Mukaiyama aldol reaction (Eq. 29). Unfortunately no enantioselectivity was observed in the aldol reaction. 

By anionic polymerization using Z-BuOK, an optically active, binaphthyl-based carbonate monomer (135) gives polymer poly-135, which has a single-handed 4i-helical conformation.238 An analogous polymer has been synthesized from a biphenyl-based monomer, 136.237 238... 

C.-P. Yang, S.-H. Hsiao, C.-Y. Tsai, G.-S. Lion, Novel, organosoluble, light-colored fluorinated polyimides based on 2,2 -bis(4-amino-2-trifluoromethylphenoxy)biphenyl or 2,2 -fc x(4-amino-2-trifluoromethylphenoxy)-l,T-binaphthyl, J. Polym. Sci., Part A Polym. Chem. 42 (10) (2004) 2416-2431. 

H. Behniafar, M. Hosseinpour, Novel ortho-linked fluorinated poly(ether-imide)s based on 2,2 -subshtuted 1,1 -binaphthyl units, Polym. Adv. Technol. 24 (1) (2013) 118-125. 

To understand further the conjugation in the binaphthyl-based polyarylenes, compounds 39 and 40 are synthesized from the reaction of 36 with 1,4-dibromobenzene and 4,4- -dibromobiphenyl, respectively 39 is the repeat unit of polymer (/ )-22 and 40 is that of polymer (/ )-23. The UV spectrum of 39 in methylene chloride solution displays a major absorption at A = 322 nm. The emission of 39 is observed at Ag ,j = 378, 396, and 417 nm when excited at 322 nm. Comparing the UV spectrum of 39 with those of (/ )-22 and rac-22, only a very small red shift ( 6 nm) from the repeat unit to the polymers is observed. The UV spectrum of 40 in methylene chloride solution shows A ,3 = 324 nm. The red shift ( 10 nm) in the absorption maxima from the repeat unit 40 to polymers (/ )-23 and rac-23 is also very small. The emission of 40 is observed at 387, 408, and 418 nm when excited at 324 nm. The absorption spectra of 39 and 40 demonstrate that the conjugation in polymers 22 and 23 is almost the same as that of their repeat units. Table 2 summarizes the UV absorption and fiuore.scence spectroscopic data for 22, 23, 39, and 40. 

E. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) Study of the Binaphthyl-Based Conjugated Polymers... 

Binaphthyl-based rigid conjugated polymers not only are potentially useful as novel electrical and optical materials but also can be applied to prepare novel polymeric... 

The use of the binaphthyl-based chiral polymers in catalysis has been explored. We have demonstrated that incorporation of aluminum metal centers into the rigid binaphthyl polymer backbones leads to greatly enhanced catalytic activity over the monomeric aluminum complex. The catalytic activity of the polymeric aluminum and titanium complexes in the Mukaiyam aldol reaction has been studied. These polymeric metal complexes represent a new generation of polymer-based catalysts... 

Scheme 21 Polymer-supported chiral binaphthyl-based Schrock catalysts.

---