Synthesis of the Carbon Framework of Scholarisine A by Intramolecular Oxidative Coupling

Scholarisine A, isolated from the leaves of Alstonia scholaris, is a monoterpene indole alkaloid with an unprecedented cage‐like structure. In this paper, preparation of the distinctive cage‐like core skeleton of scholarisine A is described. The key feature of this synthetic strategy is an intramolecular oxidative coupling reaction at the late stage to construct a 10‐oxa‐tricyclo[5.3.1.0^{3, 8}]undecan‐9‐one structure fused with indolenine. Intramolecular oxidative coupling by using N‐iodosuccinimide gave the carbon framework of scholarisine A in moderate yield, which is the first example of intramolecular oxidative‐coupling reaction between non‐activated enolate and indole. This study lays the foundation for continued investigations towards the total synthesis of scholarisine A.     

Bis(2,6-dimethoxyphenyl) sulfide, selenide and telluride, and their derivatives

2,6-Dimethoxyphenyl derivatives of sulfur, selenium, and tellurium, such as ΦEEΦ, Φ₂E, ΦSeH, [MeΦ₂E]X (X=MeSO₄, ClO₄), Φ₂EO · xH₂O, [Φ₂EOR]ClO₄, [Φ₂EOH]ClO₄ (R=Me, Et), Me₂SnCl₂ · 2Φ₂EO (E=S, Se) [Φ=2,6-(MeO)₂C₆H₃; E=S, Se, Te] have been prepared, and their properties compared with common phenyl derivatives. The reaction rates of Φ₂E with dimethyl sulfate and butyl bromide increased in the order E=S<Se<Te, which were compared with those of Ph₃M and Φ₃M, M=P>As>Sb. These reactivities are parallel with the electrochemical oxidation potentials reported for Ph₂E and with the first ionization potentials reported for Ph₃M. The rate of Φ₂Te was faster than that of Ph₃P and slightly faster than that of Φ₃Sb. From the reactivity of [Φ₂E-Me]⁺ salts with nucleophiles, the E⁺–Me bond strengths were estimated to increase in the order E=Se<S<Te. The reaction rates of Φ₂EO with dimethyl sulfate increased in the order E=S<Se<Te, and the respective rate of Φ₂EO was faster than that of Φ₂E. The origins of these reactivities and bond strengths are discussed.     

Influence of framework silica-to-alumina ratio on the water adsorption and desorption characteristics of MHI-CaX/CaY zeolite

The influence of the framework SiO₂/Al₂O₃ ratio from 2.0 to 10.0 of commercial faujasite-type CaX/CaY zeolite produced by Mitsubishi Heavy Industries Ltd. (MHI) on the water adsorption and desorption characteristics was investigated. Not only the change in electronegativity of the zeolite but the change in pore-size distribution of the zeolite affects the water adsorption and desorption characteristics of the zeolite. We found great differences in isotherms of water between CaY7.0 (SiO₂/Al₂O₃=7.0) and CaY10.0. The differences are mainly caused by the considerable change in pore-size distribution. A step-wise variation was observed in the desorption isotherm of water from CaY10.0 at approximately P/P₀=0.4. This is due to the pore distribution of CaY10.0 being relatively poor in smaller micropores in zeolite structure, since a similar phenomenon is observed in the case of argon adsorption on CaY10.0. In the experiments using a fixed bed, an apparent dependency of HTO dehydration ratio on the flow rate of the purge gas is measured with the CaY10.0 zeolite, while the water desorption from other tested CaX/CaY zeolite is independent of the flow rate of helium purge gas. This indicates that the transfer step of water diffusion through a laminar film appeared as one of the rate-controlling steps in the water desorption from CaY10.0.     

Reactivity of polyiodide toward 1, 3-bis(4-pyridyl)propane (bpp): synthesis and structure of an organic-inorganic hybrid compound [(CuI2)2(N,N′-dimethyl-bpp)] n

The solution-phase reaction of a metal iodide with 1, 3-bis(4-pyridyl)propane (bpp) yields a new organic-inorganic hybrid framework, [(CuI2)2(N,N-dimethyl-bpp)] _n (1), which is made up of organic cations [dimethyl-bpp]²⁺ and an infinite [Cu₂I₄] _n ²⁻ anion chain; The cluster 1 obtained via the reaction between polyiodide complexes and organic N-donor ligand suggests that this simple synthetic approach is likely to be applicable to the construction of polymeric clusters.Supplementary material CCDC-253123 contains the crystallographic data for this paper. These data can be obtained free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: +44-1223-336-033; E-mail: deposit@ccdc.cam.ac.uk].     

Optical fiber current sensors using garnet crystal for power distribution fields

We introduce applied examples (already put to practical use) of power distribution fields of optical fiber current sensors using iron garnet crystal that have high sensitivity, high linearity and stable temperature characteristics. We also describe two types of new optical fiber current sensors developed recently aimed at cost reduction and high performance.     

Preparation and Crystal Structural Study of a Novel Coordinated Polymer [HgI<Subscript>2</Subscript>(4-bped)<Subscript>2</Subscript>] (bped = bis(4-pyridyl)ethylene diamine)

Abstract  

A novel coordinated polymer [HgI₂(4-bped)₂] was synthesized through the reaction of bis(4-pyridyl)ethylene diamine and HgI₂ in mixed MeOH–THF (5:2). The crystal structural analysis indicated that the complex crystallized in a monoclinic space group P2₁/c, a = 10.8392(12), b = 19.841(2), c = 8.8279(10), β = 95.452(2), V = 1889.9(4) ?³, Z = 4. The complex possessed a novel three-dimensional supramolecular framework formed by hydrogen bonds among repeating [HgI₂(4-bped)]₂ dimeric units.     

PVK/C_(60)组合体系薄膜的拉曼光谱和荧光光谱研究

我们采用物理喷束淀积技术制备了Ｃ６０、Ｃ７０及聚乙烯咔唑ＰＶＫ／Ｃ６０的混合和分层薄膜，拉曼光谱的测量表明，这种技术所制备的富勒烯薄膜中，富勒烯的笼型结构仍保持完整，而在ＰＶＫ／Ｃ６０组合薄膜中，拉曼光谱及荧光光谱测量表明：在ＰＶＫ和Ｃ６０分子之间存在激发传递过程，在混合膜中，这种激发传递过程要明显强于分层组合薄膜。     

Three-dimensional formulation of time-dependent wave propagation in a gyroanisotropic medium by Bergeron''s method

This paper discusses a numerical vector analysis method for wave propagation and scattering in three-dimensional space and the time domain. The approach is based on both the equivalent-circuit representation of Maxwell's equations and the formulation by Bergeron's method in the time domain. As an example of the application of this technique to a complicated medium, we consider time-dependent electromagnetic wave propagation in a gyroanisotropic medium, specifically the magnetized ferrite and the magnetized plasma. We demonstrate that the numerical approach accurately models relevant physical phenomena, including the Faraday rotation effect.     

Enantioselective addition of diethylzinc to benzaldehyde catalyzed by a small amount of chiral 2-amino-1-alcohols

The reaction of diethylzinc with benzaldehyde catalyzed by a small amount of chiral 2-amino-1-alcohols in toluene at room temperature gave optically active 1-phenylpropan-1-ol almost quantitatively in ～, 50% ee.