Optically active polyamides

The synthesis of optically active polyamides, or nylons, is a growing area of interest. From 1980 to 1991 there have been many citations in Chemical Abstracts on this subject. For example, optically active polyamides have been prepared for the resolution of optical isomers. The polyamides are prepared from optically active amines or dicarboxylic acids. One polyamide was prepared from (-)-(ram-l,2-diaminocyclohexane and terephthaloyl chloride and was used to resolve 2,2 -dihydroxy-6,6 -dimethylbiphenyl [31]. These optically active polyamides can be used in chromatography applications to resolve other optically active compositions. 

Blaschke, G., BroekepW., FraenkefW. Chromatographic separation of race-mates. 15. HPLC separation of enantiomers on silica gel-bound optically active polyamides, Angem Chem., 1986, 98, 808-810. 

Amino acid 88 obtained from methyl 3-deoxy-3-amino-altropyranoside 87 was treated with methanesulfonyl chloride in the presence of sodium bicarbonate and gave the /3-lactam 89. Compound 89 was subsequently subjected to ring-opening polymerization to afford optically active polyamide 90... 

The synthesis of 1,6-diamino-l,6-dideoxy-2,3,4,5-tetra-0-methyl-D-mannitol and its L-iditol analogue from D-mannitol has been described [100], These diamines, containing a two-fold axis, gave stereoregular AABB polyamides on polycondensation with terephthaloyl dichloride and dipentachlorophenyl esters, or dichlorides of aliphatic dicarboxylic acids, in solution or under interfacial polycondensation conditions [99, 109]. In spite of the regioregularity present in the polymeric chains, these optically active polyamides could not be crystallized. 

Bou J.J., Rodriguez-Galdn A., Munoz-Guerra S., Optically active polyamides derived from L-tartaric add. Macromolecules, 26, 1993, 5664-5670. 

Bueno M., Zamora F., Molina 1., Orgueira H.A., Varela O., Galbis J.A., Synthesis and characterization of optically active polyamides derived from carbohydrate-based monomers, J. Polym. Sci Part A Polym. Chem., 35, 1997,3645-3653. 

S. Mallakpour, M. Dinari, Soluble new optically active polyamides derived from 5-(4-methyl-2-phthalimidylpentanoylamino)isophthalic acid and different diisocyanates under micro-wave irradiation in molten ionic liquid, J. Appl. Polym. Sci. 112 (1) (2009) 244-253. 

The monocyclopropylmethyl ester of phosphoric acid has been used for phos-phorylating nucleosides, and it provides a new and better route to nucleotides, since hydrolysis of the cyclopropylmethyl function can be readily effected in the range 2.5—2.8 pH units. Optically active polyamides have been produced from (- -)-(S)-trans-cyclopropanedicarboxylic acid. ... 

Blasclike G, Brocker W, Frankel W. Enantiomeric resolution by HPLC on sflica-gel-bound, optically active polyamides. Angew Chem Int Ed Engl 1986 25 830-1. 

With that idea, in 1958, Overberger s group undertook a program of research to study the factors contributing to the formation of preferred conformation of optically active polyamides. The synthesis and optical properties of a series of asymmetric polyamides with different degrees of structural rigidity imposed on the polymer chain, and generally also their models, have been reviewed by these authors in 1969 [49] and also by Pino [2] in 1970. The conformational aspect is treated in this book in detail, by Dr Montaudo and Dr P. Finocchiaro, and chiroptical effects independent of conformation by Dr Vert (XXI). 

A few years ago [1] the synthesis of a series of polyamides derived from optically active cyclic diacids and secondary amines (listed in Scheme 1) was undertaken in order to study the factors contributing to the formation of preferred conformations of optically active polyamides. The advantage of including optically active units into a polymer chain is immediately recognized considering that the synthesis yields a stereoregular polymer and thus... 

Another example of transforming an insoluble polymer into a soluble derivative is the A -chlorination of polyamides. Schmidt [13] has shown that ring-opening polymerization of (5 )(-)-j3-butyrolactam (1) results in an optically active polyamide II (Equation (4)). 

In spite of the dramatic changes in the CD we cannot definitely assume a change in conformation in this case. Yamaguchi [15] prepared optically active polyamides, by polycondensation of (+)-camphoryldichloride with hexamethylenediamine, which were also chlorinated in the carbonamide group [16] (III). A negative Cotton effect occurs at 218 nm... 

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