Acylperoxo-Iron(III) Porphyrin Complexes: A New Entry of Potent Oxidants for the Alkene Epoxidation
摘要:
Competitive epoxidation of norbornylene and alpha-methylstyrene by peracids in the presence of iron porphyrins has been carried out in methylene chloride and toluene at -78 degrees C. When (TMP)Fe-III(RCO(2)) (TMP = 5,10,15,20-tetramesitylporphyrin) is used as a catalyst in methylene chloride, selectivity of norbornylene oxide over alpha-methylstyrene oxide is almost identical even though a variety of peracids are used, since O=Fe(IV)TMP pi-cation radical 2a is the common oxidant in the reactions. On the other hand, the selectivity in the epoxidations catalyzed by (TDCPP)Fe-III(X) (TDCPP: 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin is found to be dependent on the structure of peracids. The latter type of the results is also obtained for the reactions catalyzed both by (TMP)Fe-III(X) and by (TDCPP)Fe-III(X) in toluene. The dependence of the selectivity in the epoxidation on the structure of peracids is attributed to the alteration of the oxidant from 2 to peracid-Fe(III) complexes 1. The direct involvement of 1 in the epoxidation has been further confirmed by spectroscopic studies of the reactions. Under the catalytic epoxidation conditions at low temperature, the participation of 1 and 2 as the active species is controlled either by electronic structure of iron porphyrin complexes (push-pull effect) or by alteration of the solvent.
SILANE COUPLING COMPOUNDS AND MEDICAL AND/OR DENTAL CURABLE COMPOSITIONS COMPRISING THE SAME
申请人:KABUSHIKI KAISHA SHOFU
公开号:US20190300552A1
公开(公告)日:2019-10-03
The present invention relate to a novel silane coupling agent and a medical and/or dental curable composition comprising the same. It is an object of the present invention to provide a novel silane coupling agent that imparts high affinity to a radical polymerizable monomer, thereby imparting high mechanical strength, flexibility and durability when used for a medical and/or dental curable composition, and an inorganic filler surface-treated with the novel silane coupling agent and a novel medical and/or dental curable composition. A silane coupling agent including repeating units such as a urethane bond and polyethylene glycol (ether bond) at a specific position is used.
The invention pertains to a method for making a fluoropolymer comprising an aqueous emulsion polymerization of one or more fluorinated monomers wherein said aqueous emulsion polymerization is carried out in the presence of at least one cyclic fluorocompound of the following formula (I):
wherein X
1
, X
2
, X
3
, equal or different from each other are independently selected among H, F, and C
1-6
(per)fluoroalkyl groups, optionally comprising one or more catenary or non-catenary oxygen atoms; L represents a bond or a divalent group; R
F
is a divalent fluorinated C
1-3
bridging group; Y is a hydrophilic function selected among anionic functionalities, cationic functionalities and non-ionic functionalities.
Expedient synthesis of oseltamivir and related compounds via direct olefin diazidation-diamidation reaction
申请人:GEORGIA STATE UNIVERSITY RESEARCH FOUNDATION, INC.
公开号:US10385010B1
公开(公告)日:2019-08-20
Disclosed herein are improved methods for the preparation of oseltamivir, and intermediates useful thereto.
本文披露了改进的奥司他韦制备方法,以及与之有关的有用中间体。
Novel proton type beta zeolite, preparation method thereof and process for preparing phenol compound using the same
申请人:UBE INDUSTRIES, LTD.
公开号:US20040242938A1
公开(公告)日:2004-12-02
Disclosed are a proton type &bgr; zeolite in which an acid site showing a desorption peak with a range of ±100° C. with a center of 330° C. exists in a spectrum measured by the ammonia temperature programmed desorption method (NH
3
-TPD), and an amount of a strong acid site showing a desorption peak of 500° C. or higher is controlled to 2.5 &mgr;mol/g or less, a method for preparing the same, and a process for preparing a phenol compound by oxidizing a benzene compound with a peroxide in the presence of the proton type &bgr; zeolite.
The present invention provides cell-laden hydrogels and hydrogel assemblies thereof for use in tissue engineering. The invention provides microscale hydrogels (i.e. microgels) having greatest dimensions ranging between about 1 μm and 1000 μm. The present invention provides methods of producing inventive hydrogels and hydrogel assemblies and pharmaceutical compositions thereof.