Studies on photocotrol of various functions at molecular level are described. The photoresponsive systems should be composed of both photosensitive and functional elements. The photosensitive elements are usually molecules which show photochromism such as azobenzene and spiropyran. The functional groups mentioned here are enzymes, inhibitors, receptors, cyclodextrins and crownethers, and the controlled functions are catalytic activity, membrane potential, viscosity, pH, conductivity, complex formation, chiral recognition and binding of metal ions.
Butadiene telomers, easily prepared by the palladium-catalyzed telomerization of butadiene with various nucleophiles are extremely useful starting materials for natural product syntheses. The following natural products were synthesized in short steps by using several butadiene telomers : Steroid (19-nortestosterone), macrolides (diplodialides, 9-decanolides, lasiodiplodin, zearalenone, recifeiolide, curvularin), Matsutake alcohol, lipoic acid, pellitorin, dihydrojasmone, methyl dihydrojasmonate, muscone, civetone, pyrethrolone, 12-acetoxy-1, 3-dodecadiene, royal jelly acids and queen substance. In these syntheses, Wacker type oxidation of terminal double bonds to methyl ketones catalyzed by PdCl2-CuCl is used in key steps.
The recently developed hydroalumination reaction of olefins catalyzed by titanium or zirconium compounds makes many organoaluminum compounds readily available and investigation up to now revealed that this new hydroalumination reaction is useful in syntheses starting from olefins. The present article reviews organic synthesis via hydroalumination which includes introduction of functional groups to the terminal carbon and lengthening the carbon chain of olefins.
Recent progress in spectroscopic and physicochemical methods to study the tautomerism of organic compounds has been reviewed. 15N-NMR has been recently applied to the study of tautomerism and proved to be a very useful technique to investigate the tautomeric behavior of nitrogen heterocycles including nucleic acid components owing to a wide chemical shift range (500 ppm). It is possible to analyze the tautomeric equilibrium quantitatively by using coupling constants of 15N-NMR. Photoelectron spectroscopy and ion cyclotron resonance technique are convenient for the investigation in gas phase. Measurement of the heat of solution in several organic solvents are useful tools for the study of highly biased equilibrium systems in non-aqueous solvents. Tautomeric equilibria are very sensitive to solvents and can be used as probes to estimate the solvent polarity and the polarity in the active site of enzymes. DNMR method, measurement of relaxation time, and temperaturejump method are available for. the study of kinetics of tautomeric interconversion. These methods are illustrated by some examples reported recently.
Recent advances of prodrug formation of therapeutic agents were reviewed with 44 references in terms of (1) improvement of stability, (2) masking of bitter taste, (3) increase of water solubility, (4) improvement of bioavailability, and (5) selective distribution into the site of action. Basic consideration for rational design of prodrug was also presented.
The following phenomena and effects useful for application to electronic devices are surveyed with organic materials : 1. Photoelectric phenomena Photoconduction, Photoelectric emission, Photovoltaic effect, Electrooptic effect 2. Thermoelectric phenomena Seebeck effect, Pyroelectric effect, Thermoresistive effect 3. Piezoelectric phenomena Piezoelectric effect, Piezoresistive effect 4. Rectification and p-n junction 5. Electric conduction Semiconduction, Metallic conduction. And a review is given of recent noticeable progress of organic electronic materials which have been put to practical uses and also have various potential applications in the field of electronics.
オレフィン・メタセシスは, 不均一触媒 (MoO3/Al2O3) によるプロピレンからエチレンとブテンを合成する「トリオレフィン・プロセス」 (1964年) で始まったが, その後均一触媒系 (たとえば, WCl6/EtOH/AlEtCl2 (Cal-deron触媒), MoCl2 (NO) 2(PPh3) 2/Al2Et3Cl3 (Hughes触媒), (OC) 5WCPh2 (Casey触媒)) やメタセシス重合の発見につづく, 各種の機構の提案があり, 有機化学者の想像力をかきたててきた。昨今, ようやくカルベン錯体機構 (Chauvin機構) に落ちつき, 本格的な有機合成反応としてのかたちをととのえてきた。将来は, 大規模な工業的反応からファインケミカル合成まで, オレフィンの合成法として極めて利用価値の高い触媒反応として成熟するものと期待され, すでに過去2回マインツとアムステルダムで国際シンポジウムが行なわれてきた。今回はISOM-3として, フランスの工業都市リヨンで, 商工会議所の後援のもと, リヨン大学商学部ホールで, 1979年9月10日～12日の3日間行なわれた。場所も時期も, ディジョンでの第9回国際有機金属会議に近く設定してあり, 関連の深い有機金属化学研究者の出席に便利にしてあった。出席者は各国から計100名以上となり, 招待講演者もN. Calderon, R. L. Banks, M. L. H. Green, C. P. Casey, R. R. Schrock, R H. Grubbsなど有名な研究者で占められ, 一つの反応に的をしぼった珍しく集中的なシンポジウムが実現した。そのため深夜近くまで活発な討論がつづいたが, 有機合成的に興味のあるものを選び報告する。
Most of alcohols and certain kinds of carboxylic acids, esters and amides depressed the tartaric acid-catalyzed decomposition of hydrogen peroxide. These compounds may affect the hydrogen bond formation, between hydrogen peroxide and tartaric acid, which promotes the decomposition.