Novel Stereoselective Synthesis of 1,3-Dienyl Tellurides by Palladium Catalyzed Cross-coupling Reaction of (E)-β-Bromovinyl Tellurides

Conjugated dienes are valuable intermediates in organic chemistry. Many biologically active compounds occurring in nature possess the structural skeleton of conjugated dienes such as chillea amide1 and pelltoine2. Besides, the synthesis of conjugated dienes for use in the Diels-Alder reaction is still an important challenge in organic synthesis. One particularly attractive approach has been the incorporation of heteroatom substituents that can activate the diene3.Recently, we found that β-br…     

A Molecular Modeling for the Complexation of Cyclobis(paraquat-p-phenylene) with Substituted Benzenes and Biphenyls

The molecular recognition of cyclobis(paraquat-p-phenylene), 14+, has drawn great attention recently, due to its important applications in the design and synthesis of electrochemically and chemically switchable rotaxanes, photoactive rotaxanes, and other molecular devices1. Usually, this type of molecular recognition was investigated with the methods including X-ray, NMR, UV, and IR. However, since these methods usually have difficulties in providing a detailed understanding of the energeti…     

One new bufadienolide biotransformed from cinobufagin by Cunninghamella elegans

Cunninghamella elegans has been employed for the biotransformation of cinobufagin （1） to afford one metabolites. The structure of the transformation product has been characterized as 7β,12β-dihydroxylcinobufagin （2）. Product 2 is a new compound. In vitro cytotoxic activities of the biotransformation product and the substrate-cinobufagin have been assayed against HeLa; they all showed cytotoxic activities.     

Solid State Synthesis and Structural Characterizationof Binuclear Cu( I)-Sb Ph_3 Co m plex 〔 Cu( Sb Ph_3)_2 I〕

１　ＩＮＴＲＯＤＵＣＴＩＯＮＣｕ（Ｉ）ｃｏｍｐｌｅｘｅｓｗｉｔｈｐｈｏｓｐｈｉｎｅａｎｄａｒｓｉｎｅｌｉｇａｎｄｓａｒｅｗｅｌｌｋｎｏｗｎ〔１〕．ＦｏｒＣｕｐｈｏｓｐｈｉｎｅｃｏｍｐｌｅｘｅｓ，ｔｈｅＣｕ∶ｌｉｇａｎｄｒａｔｉｏｖａｒｉｅｓｆｒｏｍ１∶１ｔｏ１∶４ａｎｄｃｏｏｒｄｉｎａｔｉｏｎｇｅｏｍｅｔｒｙｏｆＣｕ（Ｉ）ｒａｎｇｅｓｆｒｏｍｌｉｎｅａｒｔｏｔｒｉｇｏｎａｌ，ｔｈｅｎｔｏｔｅｔｒａｈｅｄｒａｌｅｘｔｒｅｍｅｓ；ｆｏｒｅｘａｍｐｌｅ，ｔｈｅ１∶２ａｄｄｕｃｔｓＣｕ（ＰＰｈ３）…     

Direct amination of benzene to aniline with several typical vanadium complexes

The liquid-phase direct catalytic amination of benzene to aniline was performed in acetic acid water solvent using a series of vanadium(Ⅲ,Ⅳ,Ⅴ)complexes with N,O-or O,O-ligands as catalysts and hydroxylamine hydrochloride as the aminating agent. The vanadium complexes exhibited much higher selectivity towards the production of aniline than NaVO_3 or VOSO_4.Under the optimized conditions,an aniline yield of 42.5%and a TON of 48 with a high selectivity of above 99.9%was obtained using 0.2 mmol of[VO(OAc)_2]...     

The Synthesis of 7-[1-Aza-2-(dimethylamino)vinyl]-4-methylhydroquinolin-2-ones and their Isomerism in Different Solvents

Interesting biological activities have been reported recently for 4-methylhydro-2H-pyrano [6,5-h]-chromen-2-ones and 4-methylhydro-2H-pyrano[6,5-h]quinolin-2-ones, including excellent anti-HIV activity with DCK derivatives1 and significant cytotoxic activity with 4,8,8-trimethylhydro-2H-pyrano[6,5-h]quinolin-2-one2. These results prompted us to synthesize two series of corresponding diaza three-ring heterocyclic analogs, trihydro- pyridino[2,3-h]quinolin-2-ones and hydropyridino[2,3-h]quino…     

A New Organo-Directed Titanium Phosphate Phase Containing Zigzag Chains of Corner-Sharing TiO_6 Octahedra

The chemistry of titanium phosphates has attracted considerable interests because of their applications in ion exchange, redox catalysis and outstanding non-linear optical materials. However, only a few titanium compounds have been reported, and fewer reports deal with single-crystal structure determinations due to the difficulty in obtaining large single crystals of titanium phosphates. The synthesis of titanium phosphates often leads to two-dimensional layered phases1-3, and several titanium…     

Resveratrol Tetramers from the Roots of Ampelopsis sinica

Various biological activities of stilbenoids have been described, such as antifungal and antibacterial activities1, antihepatotoxic activity2-4, anti-HIV activity5. Stilbenoids mainly existed in Vitaceae, Diperocarpaceae, Gnetaceae, Cyperaceae, Leguminase1. Many oligostilbenes have been isolated from Vitaceaeous plants. But, there was no report on the stilbenoids in Ampelopsis sinica (Miq.) W. T. Wang which was traditionari- ly used to treat arthritis6. In our study on the constituen…     

A New Flavone Glycoside from Isodon enanderianus

Isodon enanderianus (Hand.-Mazz.) H. W. Li, a perennial shrub plant of Labiatae family, is widely distributed in the southern part of Yunnan province. It has long been used as folk medicine to diminish inflammation and detoxify1. The Isodon genus is known to be rich in ent-kaurane diterpenoids, a series of new ent-kaurane diterpenoids have been isolated from the dried leaves of I. enanderianus2-4. During the course on a re-investigation of the chemical constituents of I. enanderianus, four…     

Cross-linking Copolymerization of Acrylic Acid and Multi-armed Cross-linkers

Polymer gels are of considerable interests in material science1-3. Many theoretical and experimental studies have been made on the cross-linking copolymerization4-6 of these systems. Recently, in situ interferometry is applied in studying this process7-9. As shown in Figure 1, the common two-armed cross-linkers will lead to defects in the network, while multi-armed cross-linkers will enhance the integrity of the network. This paper studies the cross-linkers influence on cross-linking and t…