73283-56-4Relevant articles and documents
Asymmetric polymerization of triphenylmethyl methacrylate leading to a one-handed helical polymer: Mechanism of polymerization
Nakano, Tamaki,Okamoto, Yoshio,Hatada, Koichi
, p. 1318 - 1329 (1992)
Asymmetric oligomerization of triphenylmethyl methacrylate (TrMA) was carried out with complexes of 9-fluorenyllithium and chiral ligands in toluene at -78°C, and the oligomers obtained were converted into methyl esters. The resulting oligo(methyl methacrylate)s were first fractionated by gel permeation chromatography in terms of degree of polymerization and further separated into diastereomers and optical isomers by high-performance liquid chromatography. The distribution of oligomers and the ratio of isomers in each oligomer gave important information on the mechanism of the asymmetric (helix sense selective) polymerization of TrMA. The reactivity of each oligomer anion depended greatly on its degree of polymerization and stereostructure. The oligomer anions whose asymmetric centers have R configuration in the system with the complex of 9-fluorenyllithium and (-)-sparteine and those of S configuration in the systems with (+)-(2S,3S)-2,3-dimethoxy-l,4-bis(dimethylamino)butane and (+)-(S)-1-(2-pyrrolidinylmethyl)pyrrolidine as chiral ligands predominantly propagated to a one-handed helical polymer. A stable helix starts at degree of polymerization 9 in the former system and at degree of polymerization 7 in the latter two systems. One helix turn seems to consist of three or four monomeric units. The main chain of the resulting polymer in the former system possessed RRR - absolute configuration and that in the latter systems SSS -, though both polymers are considered to be of the same helicity, P or M. These results indicate that the helicity of the polymer is not governed by the configuration of the main chain but by the chirality of the ligands.
One-pot preparation of alkyl iodides from esters by indium-catalyzed reductive cleavage of a carbon-oxygen bond
Sakai, Norio,Matsushita, Yohei,Konakahara, Takeo,Ogiwara, Yohei,Hirano, Keisuke
supporting information, p. 1591 - 1595 (2015/03/04)
We describe the indium-catalyzed reductive iodination of aliphatic and aromatic esters with iodine and 1,1,3,3- tetramethyldisiloxane (TMDS). This reducing procedure accommodates a variety of esters, including esters containing alkyl groups, halogens, a hydroxy group, a thioether, and an alkene moiety. Also, this procedure was applied to the cleavage of carbon-oxygen bonds in acrylate polymers.
Indium(III)-catalyzed one-pot synthesis of alkyl cyanides from carboxylic Acids
Moriya, Toshimitsu,Shoji, Kohei,Yoneda, Shinichiro,Ikeda, Reiko,Konakahara, Takeo,Sakai, Norio
, p. 3233 - 3238 (2013/12/04)
The one-pot preparation of alkyl cyanides from carboxylic acids via alkyl iodides or alkyl bromides, which were in situ generated either by indium(III)-catalyzed reductive iodination or bromination of carboxylic acids, is described. Georg Thieme Verlag Stuttgart New York.
