On the synthesis of C-glycosyl compounds containing double bonds without the use of protecting groups
作者:Günter Wulff、Guy Clarkson
DOI:10.1016/0008-6215(94)84109-8
日期:1994.4
Abstract A new range of C-glycosyl compounds carrying doublebonds have been synthesised as potential monomers for the preparation of polyvinylsaccharides. The syntheses were performed without the use of protecting groups and mostly in water as solvent. The starting material was the easily accessible 5-β- d -glucopyranosyl-1,3-dimethylbarbituric acid sodium salt (3a) (obtained from d -glucose and 1
Toward Catalytic Antibiotics: Redesign of Fluoroquinolones to Catalytically Fragment Chromosomal DNA
作者:Moshe N. Goldmeier、Sofya Katz、Fabian Glaser、Valery Belakhov、Alina Khononov、Timor Baasov
DOI:10.1021/acsinfecdis.0c00777
日期:2021.3.12
stabilization of the fluoroquinolone–topoisomerase–DNA ternary complex. Furthermore, the Cu(II) complexes of two of the new designer compounds were shown to fragment supercoiled plasmid DNA into linear DNA in the presence of DNA gyrase, demonstrating a “proof of concept” in vitro. These ciprofloxacin–nuclease conjugates can therefore serve as models with which to develop next-generation, in vivo functioning catalytic
[3.2]paracyclophane (10), [4.2]paracyclophane (14), [4.3]paracyclophane (19) as well as several derivatives of these compounds – among others the bromides 25, the ester 31, the diesters 40–43 – are described using well-established methods of cyclophane chemistry (ring-closure reactions leading to thiacyclophanes, ring contraction by sulfone pyrolysis). The parent systems and their derivatives are now
Tetrazolyl compounds and their use as anti allergic agents
申请人:Lilly Industries Limited
公开号:US04675334A1
公开(公告)日:1987-06-23
Compounds of formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are each independently selected from H, OH, C.sub.1 -C.sub.4 alkyl, R.sub.4 --CO and halogen, where R.sub.4 is C.sub.1 -C.sub.4 alkyl; R.sub.5 and R.sub.6 are each independently selected from H, C.sub.1 -C.sub.4 alkyl and optionally-substituted phenyl; R.sub.7 is an alkylene group having from 1 to 4 carbon atoms, optionally containing a substituted or unsubstituted phenyl group; p is 0 or 1; and Z is a 1H-tetrazol-5-yl or a --CN group; and salts thereof, may be prepared by reacting a compound of formula. ##STR2## with a compound of formula ##STR3## wherein R.sub.1 -R.sub.7 are as defined in claim 1, in an organic solvent at a temperature in the range of 40.degree.-120.degree. C. in the presence of a base, and reacting the resulting compound with an alkali metal cyanide or thiocyanate, and optionally reacting the resulting compound with a source of azide ions to produce pharmacologically active compounds of formula I wherein Z is 1H-tetrazol-5-yl.
The present invention provides a catalyst, which has enough catalytic activity as a transition metal particle catalyst including platinum family and the like, is easily separable from products, is reusable and is easily prepared. To prepare the transition metal cluster catalyst of the present invention, an insoluble complex is prepared by forming a complex between a polymer with nitrogen-containing group, such as pyridinium and ammonium group in the principal chain, and a later transition metal compound; and then reducing the complex with a reductant. The transition metal forms clusters, which are stabilized by the polymers. Namely, the present invention is a transition metal cluster catalyst, wherein transition metal clusters are supported by a polymer, which is obtained by reduction reaction of a complex of a transition metal and a polymer with nitrogen-containing group. The transition metal cluster catalyst of the present invention is an extremely useful catalyst for oxidation, reduction, cross-coupling, Heck reaction, alkylation reaction and the like.