1605-18-1Relevant articles and documents
Living anionic polymerization of 1,4-diisopropenylbenzene
Goseki, Raita,Onuki, Suguru,Tanaka, Shunsuke,Ishizone, Takashi,Hirao, Akira
, p. 3230 - 3238 (2015)
The anionic polymerization of diisopropenylbenzene (DIPB) derivatives was conducted in THF at -78 °C with a specially designed initiator system prepared from oligo(α-methylstyryl)lithium and an excess potassium tert-butoxide (KOBut) (2.7-5.0 equiv to the Li salt). Among the ortho-, meta-, and para-isomers of DIPB derivatives, it was found that the para-isomer (p-DIPB) successfully underwent the living polymerization in a selective manner through one of the two isopropenyl groups under the above stated conditions. With this living polymerization system, soluble polymers with controllable Mn values ranging from 7620 to 31 500 g/mol and near monodisperse distributions (Mw/Mn ≤ 1.03) were obtained for the first time. The obtained living polymers were stable at -78 °C even after 168 h and at -40 °C after 6 h, in which the intermolecular addition reaction of the chain-end anion to the pendant isopropenyl group could be completely suppressed. In contrast, the living polymerization of either the ortho- or meta-isomer was not successful under the same conditions. The block copolymerization of p-DIPB with either styrene (S), 2-vinylpyridine (2VP), or tert-butyl methacrylate (tBMA) by the sequential addition of such monomers was conducted. Four new PS-block-P(p-DIPB), P2VP-block-P(p-DIPB), P(p-DIPB)-block-P2VP, and P(p-DIPB)-block-PtBMA containing reactive P(p-DIPB) segments were synthesized. On the basis of the block copolymerization results, it is understood that p-DIPB is comparable to 2VP and located between S and tBMA in monomer reactivity. The reactivity increases as follows: S tBMA, while the nucleophilicity of the living chain-end anion decreases in the following order: PS- > P2VP- ～ P(p-DIPB) - > P(tBMA) -.
Synthesis of 2-Substituted Propenes by Bidentate Phosphine-Assisted Methylenation of Acyl Fluorides and Acyl Chlorides with AlMe3
Wang, Xiu,Wang, Zhenhua,Asanuma, Yuya,Nishihara, Yasushi
supporting information, p. 3640 - 3643 (2019/05/17)
Bidentate phosphine-assisted methylenation of acyl fluorides and acyl chlorides with substituted with aryl, alkenyl, and alkyl groups trimethylaluminum afforded an array of 2-substituted propene derivatives. The addition of a catalytic amount of DPPM increased an efficiency of the reactions. Trimethylaluminum as the methylenation reagent not only eliminates the presynthesis of methylene transfer reagent, but provides an efficient method for the synthesis of a series of 2-substituted propenes.
Nickel catalyzed cross-coupling of modified alkyl and alkenyl Grignard reagents with aryl- and heteroaryl nitriles: Activation of the C-CN bond
Miller, Joseph A.,Dankwardt, John W.
, p. 1907 - 1910 (2007/10/03)
The nickel catalyzed cross-coupling of alkyl and alkenyl Grignard reagents with aryl nitrile derivatives affords good yields of the corresponding aryl alkanes or aryl alkenes via activation of the C-CN bond. To prevent direct addition of the nucleophile to the nitrile group, the reactivity of the Grignard reagent was modulated by reaction with either LiOt-Bu or PhSLi prior to cross-coupling. The optimum catalyst was determined to be NiCl2(PMe3)2, which is a convenient air stable commercially available complex.
SELECTIVE MONO-ARYLATION AND -ALKYLATION OF CHLOROPHENYL ALKYL SULFIDES BY NICKEL CATALYSED CROSS-COUPLING WITH GRIGNARD REAGENTS
Tiecco, Marcello,Testaferri, Lorenzo,Tingoli, Marco,Chianelli, Donatella,Wenkert, Ernest
, p. 4629 - 4632 (2007/10/02)
Chlorophenyl alkyl sulfides are mono-arylated and -alkylated selectively with Grignard reagents, in the presence of Ni(PPh3)2Cl2, to give aryl- and alkyl-phenyl alkyl sulfides.
