Diacetylenes monomer synthesis

Diazido-9,9-dioctylfluorene is a common azide monomer for click coupling reactions with a diacetylene monomer. The synthesis with bis(4-methoxy-4 -hexyloxybiphenyl) dipropargyl malonate is shown in Figure 17.7. 

Extension of the reaction to diacetylene might clear the way to the ethynylpyrroles 114, promising monomers for conducting polymers and building blocks for the synthesis of new heterocycles. It turned out (76ZOR905) that, in an aqueous DMSO in the presence of catalytical amounts of KOH, diacetylene indeed added exothermically to ketoximes to form O-1 -butene-3-viny(ketoximes (113) (Scheme 54). 

As utilized in the synthesis of PPV-based polymers, soluble precursor routes have been developed for the synthesis of various heterocyclic Jt-conjugated polymers. The two most widely employed of these methods for heterocycle formation, shown in Scheme 66, center around ring closure of pre-polymers containing diacetylene 65 or 1,4-diketone units 66 [335-339]. The synthesis of heterocyclic structures from 1,4-diketones has been a known transformation in organic chemistry for decades. While once mainly used for monomer preparation through various cyclizations, it is now being employed to make heterocycle-containing polymers and copolymers [340-342]. 

In addition, the Japanese Companies, the Hitachi Chemical Co and the Mitsui Toatsu Chemical Inc. have developed interesting applications with polyimides semi-conductors, liquid crystals, poorly colorable thermostable films [103-107], Finally, let us mention monomers obtained from diamines first the synthesis of a diacetylenic compound [7] ... 

Synthesis of polydiacetylenes from novel monomers having two diacetylene units linked by an arylene group were characterized by solid-state NMR. ... 

With the development of new technologies and industrial fine synthesis, the importance of products from diacetylene as unique building blocks, synthons, and monomers will increase. And it is the small-scale production of diacetylene-based heterocyclic reagents that may become the first step in the proper industrial utilization of diacetylene. This will provide a base for launching new methods for the synthesis of a large number of valuable heterocyclic compounds that are still inaccessible from cheap industrial feedstock (00UK642). 

Polymers containing Hf(TV) in the main chain or side chains can be prepared by any of the known processes for synthesis of metal-containing polymers. An attractive approach is the polycondensation of dicyclo-pentadienyl derivatives of hafnium(IV) with diols or oxygen-free diacetylenic hgands. An alternative approach is polymerization of the Hf(TV) monomers with (meth)acrylate and fumarate groups, synthesized for the first time in this study. We investigated the thermolysis of the synthesized... 

Various polymerization route with unique starting monomer [64] have been developed, e.g., topochemical poly(diacetylene) synthesis with pyrrole-, thiophene-, -Si-groups dienophilic addition of maleic imides, Diels-Alder polymers via cyclopentadienone derivatives. 

Diacetylenes in phospholipid bilayers have been the subject of extensive studies in our laboratory, not only because of the highly conjugated polymers they form, but also because of their ability to transform bilayers into interesting microstructures. Consequent to our synthesis and characterization of several isomeric diacetylenic phospholipids, we have found that the polymerization in diacetylenic bilayers is not complete. In order to achieve participation of all diacetylenic lipid monomer in the polymerization process, diacetylenic phospholipid was mixed with a spacer lipid, which contained similar number of methylenes as were between the ester linkage and the diacetylene of the polymerizable lipid. Depending upon the composition of the mixtures different morphologies, ranging from tubules to liposomes, have been observed. Polymerization efficiency has been found to be dependent on the composition of the two lipids and in all cases the polymerization was more rapid and efficient than the pure diacetylenic system. We present the results on the polymerization properties of the diacetylenic phosphatidylcholines in the presence of a spacer lipid which is an acetylene-terminated phosphatidylcholine. 

The starting point for the preparation of polydiacetylene crystals (hereafter referred to as PDAs] is the synthesis of disubstituted diacetylenes. The synthetic routes to these compounds are well established [9] and will not be discussed here typical examples are given in Figure 1, The abbreviations given in the figure will be used to refer to particular materials below. The solid-state polymerization of the monomers proceeds... 

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