Acetylene-terminated sulfone

Eddy, L. T. R. Lucarelli, A. M. Helminiak, T. Jones, W. Picklesimer, L. F. An Evaluation of An Acetylene Terminated Sulfone Oligomer. Internal Report, A FWAL/MLBC, January 1983. 

Solid state NMR has been used to study polymers of various classes over the past several years. In particular, the technique has been used to study curing reactions in epoxies (12). polyimides (1), and acetylenic terminated sulfones (13). The ability to observe the evolution of the carbons of the reacting species has been clearly shown to provide valuable information which has been difficult or impossible to obtain with other techniques. The use of 13C solid state NMR techniques is essential for the understanding of curing reactions in high temperature polymers in order to be able to correlate the reaction chemistry with the structural and resulting physical properties. 

Acetylene-terminated resins (ATR) bisphenol-based, synthesis, 17-29 thermally curable, 6 Acetylene-terminated sulfone (ATS), thermally curable, 5 Acid values, castor oil prepolymer formation, 241 Addition polymerization... 

Multiple scan DSC curves at various heating rates were utilized to obtain kinetic parameters for an acetylene terminated sulfone (ATS) which were compared with isothermal reaction rates. The comparison between scanning and isothermal reaction kinetics illustrated the retarding effect of incipient vitrification of the ATS on the reaction rate. 

Recent advances in acetylene terminated resin technology have provided a family of new high performance structural materials (U2). One member of this family, the acetylene terminated sulfone ( TS) 3) has been made available in sufficient quantities to allow research efforts on characterization and determination of the effects of structure on physical and mechanical properties ( - ). In a companion paper (t) the effects of environment on the cure of ATS was reported. This paper reports... 

The circles show measurements of a determined by the disappearance of the acetylene IR band at 941 cm ( ). The squares show the DSC residual heat measurements. It should be noted that a problem occurs in the analysis of the DSC data since another exotherm is observed in acetylene terminated sulfones at higher temperatures than the reaction exotherm but sufficiently low so as to overlap with the end of the reaction exotherm. The residual heat data were determined by estimating the contribution of the second exotherm and graphically subtracting it from the total heat evolved. While this approximate method produces considerable scatter in the data, it appears to agree quite well with the infrared data. 

Jones, W. B., et. al., "Evaluation of an Acetylene Terminated Sulfone Oligomer," presented at American Chemical Society Meeting, March 1980, Houston, TX. 

Acetylene terminated monomers, e.g., acetylene terminated sulfone are known to exhibit high thermal stability, good adhesion characteristics and high moisture resistance (.6,7). Starting with bls-phenol fluorenone we synthesized acetylene terminated fluorenone (ATF). 

Polysulfones have been made from acetylene-terminated sulfone monomers (Fig. 3.51), and cured graphite-fiber laminates have shown Tg = 300°C and good mechanical properties at 170°C before and after heat and humid aging. Semi-interpenetrating polymer networks with linear thermoplastic polysulfones showed promise of combining the heat deflection temperature and solvent-resistance of the thermoset polymer with the impact resistance of the thermoplastic. 

Arylether Sulfone Oligomers with Acetylene Termination from the Ullman Ether Reaction... 

Both terminal and nonterminal acetylenes have been used. Activating groups oL to the acetylenic bond have included sulfone (131-135), sulfoxide (134), ester (28,133-139), and ketone (134,140). Whether adduct 183 Is designated as cis or trans depends on the investigators and the particular compound. If the addition reaction is carried out in aprotic solvents, the major isomer is 183 formed by cis addition (135,138,139). For example, the addition of aziridine to dimethyl acetylenedicarboxylate (182, X, Y = CO2CH3) in dimethyl sulfoxide (135) gave 75 % of a mixture containing 95 % of the Chester 185. Collapse of the intermediate zwitterion intermediate 186... 

The most convenient method of preparing the flexible (low Tg) system is to employ the Ullmann ether reaction of dibromobenzene and aromatic bis-diols followed by catalytic replacement of the bromine atoms by terminal acetylene groups. A host of commercially available bis-diols have been used in the synthesis with both meta and para dibromobenzene. Low Tg arylether oligomers have been prepared containing sulfone, sulfide, carbonyl, isopropyl and perfluoroisopropyl groups in the backbone (9). 

These are good dienophiles. and aryl vinyl sulfones have found use as equivalents of ethylene and ketene through functional modifications of their adducts. However, as the base-induced elimination of a sulfinic acid to yield an olefin occurs only with difficulty, they are not direct precursors of acetylene equivalents, unless suitably modified as in ( )-l-phenyl-sulfonyl-2-trimethylsilyl ethylene (PhS02-CH=CH-TMS). In its cycloadducts the elimination to an alkene is smoothly realized by the fluoride ion. If an alkylation step is previously carried out on the adduct, the overall process realizes an indirect addition of a terminal acetylene, as in the examples given here [533]. 

Vinyl sulfones in general serve as excellent dienophiles in Diels-Alder reactions,4 and we5 and others2-4 have found the resultant cyclohexene to contain very useful functionality for further manipulation. Hence the vinyl sulfone moiety can serve as a synthon for ethylene,6 terminal olefins,7 acetylene,8 and vinylsilanes9 in [4+2]-cycloadditions as well as valuable synthetic intermediates in general.10... 

Air, the cheapest oxidant, is used only rarely without irradiation and without catalysts. Examples of oxidations by air alone are the conversion of aldehydes into carboxylic acids (autoxidation) and the oxidation of acyl-oins to a-diketones. Usually, exposure to light, irradiation with ultraviolet light, or catalysts are needed. Under such circumstances, dehydrogenative coupling in benzylic positions takes place at very mild conditions [7]. In the presence of catalysts, terminal acetylenes are coupled to give diacetylenes [2], and anthracene is oxidized to anthraquinone [3]. Alcohols are converted into aldehydes or ketones with limited amounts of air [4, 5, 6, 7], Air oxidizes esters to keto esters [3], thiols to disulfides [9], and sulfoxides to sulfones [10. In the presence of mercuric bromide and under irradiation, methylene groups in allylic and benzylic positions are oxidized to carbonyls [11]. 

Oxidations by oxygen and catalysts are used for the conversion of alkanes into alcohols, ketones, or acids [54]-, for the epoxidation of alkenes [43, for the formation of alkenyl hydroperoxides [22] for the conversion of terminal alkenes into methyl ketones [60, 65] for the coupling of terminal acetylenes [2, 59, 66] for the oxidation of aromatic compounds to quinones [3] or carboxylic acids [65] for the dehydrogenation of alcohols to aldehydes [4, 55, 56] or ketones [56, 57, 62, 70] for the conversion of alcohols [56, 69], aldehydes [5, 6, 63], and ketones [52, 67] into carboxylic acids and for the oxidation of primary amines to nitriles [64], of thiols to disulfides [9] or sulfonic acids [53], of sulfoxides to sulfones [70], and of alkyl dichloroboranes to alkyl hydroperoxides [57]. 

The procedure for oxidation of the sulfide to the sulfone is based on that reported earlier by Bordwell and Pitt. The synthetic utility of phenyl vinyl sulfone and sulfoxide derives not only from their ability to serve as excellent Michael acceptors toward such reagents as enolate anions and organometallics, but also as moderately reactive dienophiles in Diels-Alder reactions. " The resulting adducts, in turn, can be chemically modified so that these electron-deficient olefins serve as useful synthons for acetylene,ethylene,terminal olefins,vinylsilanes, and ketene in [4 + 2] cycloadditions. Phenyl vinyl sulfone undergoes ready cycloaddition to Danishefsky s diene in the first step of a protocol for the regiospecific y-alkylation of 2-cyclohexenones. Furthermore, the ready lithiation of phenyl... 

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