TSUNO Yuho Kyushu University, Faculty of Science (Professor), 理学部, 教授 (10029845)
MARUYAMA Kazuhiro Kyoto University, Faculty of Science (Professor), 理学部, 教授 (90025263)
IWAMURA Hiizu The Institute for Molecular Science (Professor), 分子科学研究所, 教授 (10011496)
INAMOTO Naoki The University of Tokyo, Faculty of Science (Professor), 理学部, 教授 (30011422)
SAKURAI Hideki Tohoku University, Faculty of Science (Professor), 理学部, 教授 (70025873)
1. Various novel organic compounds containing hetero atoms were synthesized in order to investigate new and interesting properties which can be ascribed to the hetero atom such as silicon, sulfur, selenium, tellurium, phosphorus, antimony and etc. There were found evidence for a strong <sigma> / <pi> interaction in some silicon compounds. Some lower coordinated phosphorus compounds were prepared on the basis of sterically protected functionality and they have unusual chemical behaviors. Hypervalent compounds (sulfurane, phosphorane, stiborane, etc.) were formed by means of five-membered ligands. Many small ring compounds containing hetero atoms were also studied vigorously. A catalytic reaction from amine and carbon monoxide into urea occurred in the presence of selenium. Debromination of organic compounds was developed by using sodium telluride or triarylstibine and their reaction mechanisms were clarified. 1,2-Stereospecific reactions were designed in pinacol type rearrangement with
alkyl aluminum reagents.
2. Several synthetic reactions were developed by means of organo transition metal catalysts such as cobalt, paradium, ruthenium, zirconium and etc. There were interconversion between functional groups, synthesis of heterocycles, insersion of carbon monoxide, and ring-expansion of metal-diene complexes. New design of ligand such as porphyrin, phosphine, and macrocyclic polyamine developed some interesting photoreactions, useful asymmetric reactions, and novel functions. Furthermore, high-spin organic molecules were designed and synthesized and their magnetic behaviors were studied.
3. Substituent effects in heterocyclic compounds, solute-solvent interactrions in organic compounds, and physicochemical behaviors of radicals participated with hetero atoms were discussed from standpoint of reaction mechanism. Hypervalent structure of some organic sulfur compounds was confirmed by means of X-ray crystal analysis. The classical concept of the oxidation number was interpreted theoretically. Structure and relative stability of unprecedented molecules and reactive intermediates containing hetero atoms were determined theoretically with ab initio calculation. Less