Reaction of α-(trifluoromethyl)styrene with anionic initiators

Abstract

a-(Trifluoromethyl)styrene (Q = 0.43, e = 0.90) does not undergo radical homopolymerization. Anionic polymerization fails to produce appreciable amounts of polymer even in bulk at -78 °C in spite of its high e value. The resistance to anionic polymerization is primarily due to side reactions involving addition-elimination sequences (Sn2') when initiators are nucleophilic enough to add to the 3-carbon of TFMST. Weaker anionic initiators such as pyridine and potassium terf-butoxide that effectively induce polymerization of methyl a-(trifluoromethyl)acrylate (Q = 0.74, e = 2.5) do not react with TFMST. Reactions of TFMST with several anionic initiators are described in detail.

Synthesis of α-trifluoromethylstyrene derivatives via Ni-catalyzed cross-coupling of 2-bromo-3,3,3-trifluoropropene and aryl Grignard reagents

“…a-Trifluoromethylstyrene was detected by GC and 19 F NMR in any solvents. It should be mentioned that byproducts formed by the cleavage of C-F bonds of a-trifluoromethylstyrene [6] were not detected [4]. Polar and basic solvents (NMP, DMPU and DMI) gave the higher yields (entries 5-7) than the other solvents commonly used in Grignard reactions (entries 1-3) and 1,4-dioxane (entry 4) in which the Pd-catalyzed coupling occurred exclusively [4].…”

“…In addition, by-products, which are formed by the reaction of atrifluoromethylstyrene and phenylmagnesium bromide (PhMgBr) [6], were not detected by GC and 19 F NMR at all. On the other hand, the combination of Ni catalysts and Grignard reagents are known to cleave frequently C-F bonds in alkyl fluorides [7].…”

Acid‐catalyzed degradation mechanism of poly(phthalaldehyde): Unzipping reaction of chemical amplification resist

“…[3][4][5][6] While end-capped poly(phthalaldehyde) is thermally stable up to Construction of Two Reaction Model Compounds 200ЊC, 1,2 the relief images made of such chemically amplified resists are developed thermally at Since photoirradiation on the resist causes acid-Ç 100ЊC. [3][4][5][6] This indicates that a acid-catalyzed generation in the resist, one of oxygens in enddegradation mechanism operates definitely in the capped poly(phthalaldehyde) is protonated at first. dry-developed process.…”

Novel Fluoropolymers for Use in 157nm Lithography.

“…Because of its very low electron density (e=2.5) [8], however, MTFMA undergoes anionic polymerization readily with amines and organic/inorganic salts complexed with 18-crown-6 [4]. While these are unconventional anionic initiators for vinyl monomers, typical anionic initiators such as alkyllithium and Grignard reagents fail to polymerize MTFMA due to SN-2' addition-elimination [4,9]. PMTFMA synthesized in 1985 by anionic polymerization with potassium tbutoaude was subjected to UV measurements at 157 nm.…”