Phosphorus‐Containing Block Copolymers from the Sequential Living Anionic Copolymerization of a Phosphaalkene with Methyl Methacrylate

Abstract

Althoughl ivingp olymerization methods are widely applicable to organic monomers, their applicationt o inorganic monomers is rare. For the first time, we show that the living poly(methylenephosphine) (PMP n À )a nion can function as am acroinitiator for olefins.S pecifically,t he phosphaalkene, MesP=CPh 2 (PA), and methyl methacrylate (MMA) can be sequentially copolymerized using the BnLi-TMEDA initiator system in toluene. As eries of PMP n -b-PMMA m copolymers with narrow dispersities are accessible ( = 1.05-1.10).Analysis of the block copolymers provided evidence for -P-CPh 2 -CH 2 -CMe(CO 2 Me)-switching groups.I mportantly,t his indicates that the -P-CPh 2 À anion directly initiates the anionic polymerization of MMA and stands in stark contrast to the isomerization mechanism followed for the homopolymerization of PA.F or the first time, the glass transition of a PMP n homopolymer has been measured (T g = 45.1 8C, n = 20). The PMP n -b-PMMA m copolymers do not phase separatea nd show as ingle T g which increases with higherP MMA content.Scheme1.Anionic polymerization of RP=CAr 2 (R = Mes or o-Xyl).

Thorium(IV) and Uranium(IV) Phosphaazaallenes

“…The reactivity of metal-phosphido complexes is of interest for the development of hydrophosphination catalysts as well as the synthesis of phosphorus-element multiple bonds. For example, phosphaalkenes, P=C, have attracted interest for building blocks in organophosphorus chemistry [1][2][3], ligands to transition metal complexes [4,5], as well as potential applications as functional materials [6][7][8][9][10]. After nearly 20 years of dormancy [11][12][13][14][15], actinide-phosphorus has received greater attention recently [16][17][18][19] with researchers examining similarities and differences in the molecular and electronic structure of its more studied congener, nitrogen.…”

Diastereoselective Synthesis of Spirodihydrobenzofuran Analogues of the Natural Product Filifolinol

“…To overcome this problem, the use of chelating agents, such as tetramethylethylenediamine (TMEDA) has been reported to increase the reactivity of organolithium reagents. [26] Thus, we modified our original proposal and benzyllithium, prepared in situ from toluene and n-buthyllithiium (n-BuLi) in presence of TMEDA, was used instead of benzyl bromide 4 and allowed to react with compound 3 (Scheme 3). Based on this methodology a white solid compound was obtained from a complex mixture in a moderate 40 % of yield.…”

“…We reasoned that the low yield of the reaction was due the low concentration of the Li + species in the reaction media. To overcome this problem, the use of chelating agents, such as tetramethylethylenediamine (TMEDA) has been reported to increase the reactivity of organolithium reagents [26] . Thus, we modified our original proposal and benzyllithium, prepared in situ from toluene and n‐buthyllithiium (n‐BuLi) in presence of TMEDA, was used instead of benzyl bromide 4 and allowed to react with compound 3 (Scheme 3).…”

Coordination-induced polymerization of P═C bonds leads to regular (P─C) n polycarbophosphanes

“…1B) with mesityl (Mes) substituent at P and variable substituents R on carbon (R = phenyl, 9-phenanthryl, 4-methoxyphenyl, 1-naphthyl, ferrocenyl, pyrenyl, and oxazoline-derived groups) were polymerized or copolymerized. The initial assumption that these polymers contain a regular (P─C) n backbone had to be corrected (14,15). Instead, a complex polymerization process that involves isomeri-zation takes place, leading to polymers with an irregular microstructure as shown in Fig.…”