The stereochemical control of aldol reactions from unsubstituted enolor enolatelike species, what are known as acetate aldol reactions, has been a matter of concern for nearly 30 years [1, 2]. Indeed, pioneering studies soon recognized that the asymmetric installation of a single stereocenter in such aldol reactions was much more demanding than the simultaneous construction of two new stereocen...

The density functional theory (DFT) model ONIOM(M06L/6-311++G(2df,2p):UFF was employed to reveal the catalytic activity of Cu(II) in the paddle-wheel unit of the metal-organic framework (MOF)-505 material in the Mukaiyama aldol reaction compared with the activity of Cu-ZSM-5 zeolites. The aldol reaction between a silyl enol ether and formaldehyde catalyzed by the Lewis acidic site of both mater...

On the other hand, the less stabilized tris(4chlorophenyl)methyl cation (1 b) was reported to initiate the polymerization of isobutene3). In accordance, p-methoxy and p-methyl substituted tritylium ions do not initiate the polymerization of a-methylstyrene, in contrast to the less stable 1 a and 1 b4). Only for few reactive monomers, however, the initiation was proven to proceed via addition of...

Treatment of selected aldehydes and ketones with cyanotrimethylsilane in the presence of the microporous metal-organic framework Mn3[(Mn4Cl)3BTT8(CH3OH)10]2 (1, H3BTT = 1,3,5-benzenetristetrazol-5-yl) leads to rapid conversion to the corresponding cyanosilylated products. The transformation is catalyzed by coordinatively unsaturated Mn2+ ions that serve as Lewis acids and lead to conversion yie...

Kozushima is a volcanic island, located in the northern part of Izu Islands, approximately 170 km SSW central Tokyo. The volcanism Volcano started at 80-60 ka and formed monogenetic volcanoes. latest eruption occurred AD 838, was associated with formation lava dome pyroclastic cone Tenjo-san. In order to contribute long-term forecasting eruptions on Islands off Tokyo, tephrostratigraphy history...