This Perspective presents the development in living anionic polymerization since 1990. The main subjects involve following concerns of polymerization: functional styrene derivatives, new monomers and promising additives, regio- stereoselective polymerization, special polymers having rigid-rod-like or helical conformations, synthesis complex branched composed comblike segments via poly(macromonomer)s, precise macromolecular architectures including multiblock polymers, exact graft...

A. Hirao, S. Itsuno, Nakahama and N. Yamazaki, J. Chem. Soc., Commun., 1981, 315 DOI: 10.1039/C39810000315

The asymmetric reduction of aromatic and aliphatic ketones, halogeno hydroxy keto esters, ketone oxime ethers with reagents prepared from borane chiral amino alcohols has been investigated. When α,α-diphenyl β-amino alcohols, such as (2S,3R)-(–)-2-amino-3-methyl-1,1 -diphenylpentanol (2d), were used a auxiliary, very high enantioselectivities (ca. 90 % e.e.) obtained in the various ketones ethers.

Abstract In the presence of optically active amino alcohol–borane complex, an oxime ether was reduced with various hydride reducing agents to give a chiral primary amine high optical purity. Catalytic use complex also investigated.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolymerization of monomers containing functional silyl groups. 5. Synthesis new porous membranes with groupsJae Suk Lee, Akira Hirao, and Seiichi NakahamaCite this: Macromolecules 1988, 21, 1, 274–276Publication Date (Print):January 1988Publication History Published online1 May 2002Published inissue 1 January 1988https://doi.org/10.1021/ma00179a057RIGHTS & PERMISSIONSArticle Views921Altmetric-Citations145LEARN ABOUT THESE METRICSArticle Views are...

Asymmetric reduction of prochiral aromatic ketones with the reagent prepared from (S)-(–)-2-amino-3-methyl-1,1-diphenylbutan-1-ol [(S)-(1)] and borane afforded corresponding secondary alcohols in high optical (94–100% enantiomeric excess) chemical (100%) yields.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics of Chain Coupling at Melt InterfacesP. Guegan, C. W. Macosko, T. Ishizone, A. Hirao, and S. NakahamaCite this: Macromolecules 1994, 27, 18, 4993–4997Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August 1994https://pubs.acs.org/doi/10.1021/ma00096a022https://doi.org/10.1021/ma00096a022research-articleACS PublicationsRequest reuse permissionsArticle...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAsymmetric reduction of aliphatic ketones with the reagent prepared from (S)-(-)-2-amino-3-methyl-1,1-diphenylbutan-1-ol and boraneShinichi Itsuno, Koichi Ito, Akira Hirao, Seiichi NakahamaCite this: J. Org. Chem. 1984, 49, 3, 555–557Publication Date (Print):February 1, 1984Publication History Published online1 May 2002Published inissue 1 February 1984https://pubs.acs.org/doi/10.1021/jo00177a036https://doi.org/10.1021/jo00177a036research-articleACS...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolymerization of monomers containing functional groups protected by trialkylsilyl groups. 5. Synthesis poly(2-hydroxyethyl methacrylate) with a narrow molecular weight distribution means anionic living polymerizationAkira Hirao, Hideshige Kato, Kazuo Yamaguchi, and Seiichi NakahamaCite this: Macromolecules 1986, 19, 5, 1294–1299Publication Date (Print):May 1, 1986Publication History Published online1 May 2002Published inissue 1...

We report the nonvolatile memory characteristics of pentacene-based organic field-effect transistors (OFET) using polystyrenepara-substituted with π-conjugated oligofluorenes (P(St-Fl)n (n = 1–3)) as chargeable polymer electrets. Effects fluorene conjugated length on surface structure and pentacene OFET were investigated. Among these electrets, device P(St-Fl) exhibited highest mobility 0.47 cm2 V−1 s−1 due to largest grain size growth. The P(St-Fl)3 revealed hysteresis window 76 V it having...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of Side-Chain Liquid Crystalline Homopolymers and Block Copolymers with Well-Defined Structures by Living Anionic Polymerization Their Thermotropic Phase BehaviorMasayuki Yamada, Akira Hirao, Seiichi Nakahama, Tsukasa Iguchi, Junji WatanabeCite this: Macromolecules 1995, 28, 1, 50–58Publication Date (Print):January 1995Publication History Published online1 May 2002Published inissue 1 January...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of polymers with amino end groups. 3. Reactions anionic living α-halo-ι-aminoalkanes a protected functionalityKenji Ueda, Akira Hirao, and Seiichi NakahamaCite this: Macromolecules 1990, 23, 4, 939–945Publication Date (Print):February 1, 1990Publication History Published online1 May 2002Published inissue 1 February 1990https://pubs.acs.org/doi/10.1021/ma00206a006https://doi.org/10.1021/ma00206a006research-articleACS PublicationsRequest...

Novel 3-arm ABC, 4-arm ABCD, and 5-arm ABCDE asymmetric star polymers comprising the conductive polyacetylene precursor, poly(4-methylphenyl vinyl sulfoxide) (PMePVSO), other segments, such as polystyrene, poly(α-methylstyrene), poly(4-methoxystyrene), poly(4-trimethylsilylstyrene), poly(4-methylstyrene), were synthesized by methodology based on living anionic polymerization using DPE-functionalized polymers. This involves addition reaction of a polymer to followed MePVSO initiated from in...

Abstract Anionic polymerization of 4‐( tert ‐butyldimethylsilyloxy)styrene ( 2 ) was investigated under high vacuum conditions (≈ 10 −6 mbar). readily polymerized by lithium naphthalide to form a “living polymer” at −78°C. By subsequent acid hydrolysis the resulting polymer, linear, nearly monodisperse polymer 4‐vinylphenol known molecular weight obtained. Block copolymers with α‐methylstyrene were also prepared means this living system.

The asymmetric reduction of aromatic ketones with the reagents prepared from borane and chiral aminoalcohols was studied under various conditions. ratio to (S)-valinol found be optimum at 2–3:1, when up 65–73% selectivity obtained in n-propyl phenyl ketone. amino-alkoxy-amine-boranes (2) and/or (3) were tentatively proposed as reaction species responsible for induction.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolymerization of monomers containing functional silyl groups. 7. Porous membranes with controlled microstructuresJae Suk Lee, Akira Hirao, and Seiichi NakahamaCite this: Macromolecules 1989, 22, 6, 2602–2606Publication Date (Print):June 1, 1989Publication History Published online1 May 2002Published inissue 1 June 1989https://pubs.acs.org/doi/10.1021/ma00196a010https://doi.org/10.1021/ma00196a010research-articleACS PublicationsRequest reuse...

Chiral polymeric reagents have been prepared from (S)-prplinols and borane used in the enantioselective reduction of a series prochiral ketones under various conditions. Reductions with these are shown to give alcohols reasonably good optical purity (up 80%). The results compared those obtained (S)-N-benzylprolinol–borane complex which is soluble model reagent.

We investigated the rheology of a series anionically synthesized, model symmetric Cayley tree poly(methylmethacrylates) having from 1 to 4 generations identical molar mass. The hierarchical relaxation different was assessed linear data by accounting for both plateau modulus and characteristic times. Using tube-model time-marching analysis based on concept hierarchy motion, we described quantitatively frequency spectra without adjustable parameters. also performed uniaxial extensional...

This article reviews the synthesis of well-controlled graft polymers by living anionic polymerization towards exact polymers. The structure a polymer is defined following three parameters: (1) molecular weight main chain, (2) and (3) placement chain. Based on these parameters, extent structural control synthesized so far described. Finally, recently (co)polymers stepwise iterative methodologies are introduced. In their structures, parameters perfectly controlled.