Metalated phenylsulfone

This paved the way for an Sn2 displacement with potassium thiophen-oxide, and sulfide oxidation to obtain phenylsulfone 5. Metallation of 5 was accomplished at —78°C with M-butyllithium in tetrahydrofuran (THF). The resulting a-phenylsulfonyl anion added readily to aldehyde 8 to afford a mixture of P-alkoxysulfones that underwent smooth O-acylation with acetic anhydride. The mixture of p-acetoxysulfones so formed was then reacted with 6% Na/Hg amalgam in methanol and ethyl... 

Only a limited number of vinylsulfones (e.g. mms-2-phenylvinyl-phenylsulfone) undergo codimerization with methylenecyclopropane. In most cases they are too strongly bound to the metal, preventing an interaction with methylenecyclopropane. In the case of alkyl-substituted vinylsulfones the Pd(0) catalyzed isomerization to allylsulfones is faster than cycloaddition 194). 

Originally the phenylsulfone 147 Ar=Ph was used and the adduct was acylated then treated with dissolving metal (e.g. sodium amalgam) to bring about a reductive elimination by electron transfer. Addition of two electrons to 151 gives the dianion 152 that breaks down to the carbanion 153 or something like it - at any rate without stereochemistry - and so to the alkene. 

More recent studies have been concerned with the utilization of acetylene functionality and designing a system which would have all the processing criteria of an epoxide system. Materials which process analogously to the state-of-the-art epoxides require a very flexible backbone which will exhibit a low Tg before cure. The study provided a flexible aryl-ether system which Incorporates a phenylsul-fone backbone and has been referred to as ATS. The initial synthesis of ATS Involved the nucleophilic displacement reaction of various leaving groups in the 4,4 positions of diphenylsulfone with the metallic salt of m-hydroxyphenylacetylene. Research in our laboratory for lower cost precursors to ATS has led to the synthesis of bromo end-capped phenylsulfone oligomers via the Ullmann ether synthesis. 

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