Shigeru Yamago

Square goes to loop: A selective synthesis of [8]cycloparaphenylene under mild and neutral reaction conditions was achieved in a small number of steps and in a high yield through the square-shaped platinum biphenyl intermediate 1. Compound 1 is the smallest cycloparaphenylene derivative synthesized to date. Hoop-shaped π-conjugated molecules have attracted the attention of theoretical, synthetic, and supramolecular chemists for more than a half century because of their unique structures which ha

For sorting peas: When a mixture of cycloparaphenylenes (CPPs) is treated with C60, [10]CPP selectively encapsulates C60 forming the shortest fullerene-peapod, [10]CPP⊃C60 (see picture). Such complementary host–guest complexes could be useful for the size- and shape-selective separation of higher fullerenes and carbon nanotubes. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTPrecision Polymer Synthesis by Degenerative Transfer Controlled/Living Radical Polymerization Using Organotellurium, Organostibine, and Organobismuthine Chain-Transfer AgentsShigeru Yamago*View Author Information Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan* To whom correspondence should be addressed. E-mail: [email protected]Cite this: Chem. Rev. 2009, 109, 11, 5051–5068Publication Date (Web):August 28, 2009Publication

Polymer-end mimetic organotellurium compounds initiate controlled/living radical polymerization of styrene derivatives that allows accurate molecular weight control with defined end-groups. Transformations of the end-groups via radical and ionic reactions provide a variety of end-group modified polystyrenes.

This article describes the most recent developments in the synthesis of three-dimensional π-conjugated molecules and the elucidation of their properties made by our research group. Various cycloparaphenylenes (CPPs) of different sizes and a cage-like 3D molecule were synthesized based on the platinum-mediated assembly of π-units and subsequent reductive elimination of platinum. The assembly of π-units by this method mimics the self-assembly process for the formation of supramolecular ligand-meta

The size- and orientation-selective formation of the shortest-possible C70 peapod in solution and in the solid state by using the shortest structural unit of an "armchair" carbon nanotube (CNT), cycloparaphenylene (CPP), has been studied. [10]CPP and [11]CPP exothermically formed 1:1 complexes with C70 , thereby giving the resulting peapods. A van't Hoff plot analysis revealed that the formation of these complexes in 1,2-dichlorobenzene was mainly driven by entropy, whereas the theoretical calcu

A new versatile method for conducting living radical polymerization has been developed in which organostibines induce consecutive group-transfer radical reactions with alkenes. The method has been successfully applied, for the first time, to the controlled polymerization of both conjugated and unconjugated vinyl monomers, and the desired polymers with predetermined molecular weight and low polydispersity index were obtained in excellent yields. This characteristic feature of this method is exemp

Vom Quadrat zum Kreis: Die selektive Synthese von [8]Cycloparaphenylen unter milden und neutralen Reaktionsbedingungen gelang in wenigen Stufen und hoher Ausbeute über das quadratförmige Biphenylplatin-Intermediat 1 (siehe Schema). 1 ist das kleinste bisher hergestellte Cycloparaphenylen. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the author

The organotellurium-mediated living radical polymerization (TERP) method allows the synthesis of various polyacrylate and polymethacrylate derivatives with precise control of molecular weight and with defined end groups. The method can be applied to the synthesis of AB-diblock and ABA- and ABC-triblock copolymers composed of different families of monomers.

UV-vis irradiation of an organotellurium chain transfer agent in the presence of vinyl monomers leads to the formation of highly controlled living polymers with predetermined number average molecular weights and narrow molecular weight distributions.

Abstract Organotellurium‐mediated living radical polymerizations (TERPs) and organostibine‐mediated living radical polymerizations (SBRPs) provide well‐defined polymers with a variety of polar functional groups via degenerative chain‐transfer polymerization. The high controllability of these polymerizations can be attributed to the rapid degenerative‐transfer process between the polymer‐end radicals and corresponding dormant species. The versatility of the methods allows the synthesis of AB dibl

The effects of photoirradiation in controlled and living radical polymerization (LRP), namely nitroxide-mediated polymerization (NMP), atom-transfer radical polymerization (ATRP), cobalt-mediated radical polymerization (CMRP), reversible addition-fragmentation chain transfer polymerization (RAFT), organoiodine-mediated radical polymerization (IRP), and organotellurium-mediated radical polymerization (TERP), are summarized. As in the conventional radical polymerization, photoirradiation has been

The living end: Organobismuthines promote highly controlled living radical polymerization through two activation mechanisms, namely, thermal generation and degenerative transfer (see scheme). Both conjugated and nonconjugated vinyl monomers are polymerized to give well-defined polymers with predetermined molecular weight (Mn) and low polydispersity index (PDI).

Cyclic precursors of cycloparaphenylenes (CPPs) containing 1,4-dihydroxy-2,5-cyclohexadien-1,4-diyl units are prepared by modifying a synthetic method developed by Jasti and co-workers for the synthesis of corresponding 1,4-dimethoxy derivatives. Reductive aromatization of the diyl moieties by SnCl2/2 HCl takes place under mild conditions and affords the CPPs in good yields, incorporating 5 or 7-12 phenylene units. Highly strained [5]CPP is synthesized in greater than 0.3 g scale. (119)Sn NMR sp