- Aqueous reductive amination using a dendritic metal catalyst in a dialysis bag
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Water-soluble dendritic iridium catalysts were synthesized by attaching a reactive metal complex to DAB-Am dendrimers via an adapted asymmetric bipyridine ligand. These dendritic catalysts were applied in the aqueous reductive amination of valine while contained in a dialysis bag. Comparable conversions were observed as for the noncompartmentalized counterparts, albeit with somewhat longer reaction times. These results clearly show that the encapsulated catalyst system is suitable to successfully drive a complex reaction mixture with various equilibrium reactions to completion.
- Willemsen, Jorgen S.,Van Hest, Jan C.M.,Rutjes, Floris P.J.T.
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supporting information
p. 960 - 965
(2013/06/27)
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- PROCESS FOR PREPARATION OF ALKYL METHANESULFONATE SOLUTION
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An aromatic organic solvent solution of a methanesulfonic acid alkyl ester having high thermal stability is obtained by reacting an alkyl alcohol with methanesulfonyl chloride in an aromatic organic solvent in the presence of a tertiary amine, and washing the resulting aromatic organic solvent solution of a crude methanesulfonic acid alkyl ester with an aqueous alkali metal carbonate solution. The washing is performed using the aqueous alkali metal carbonate solution having a concentration of 1 to 3 mass% in an amount of 4 to 6 parts by mass per 1 part by mass of the alkyl alcohol.
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Paragraph 0028; 0029
(2013/03/26)
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- Novel convenient synthesis of biologically active esters of hydroxylamine
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Alkylation of ethyl N-hydroxyacetimidate with readily available methanesulfonates of functionally substituted alcohols and subsequent deprotection of aminooxy group is a novel and convenient method to prepare functionally substituted esters of hydroxylamine with high overall yield. This approach is a good alternative to wellknown reaction of N-hydroxyphthalimide with alcohols under the Mitsunobu conditions. The properties of ethoxyethylidene protection of aminooxy group on the contrary to that of N-alkoxyphthalimide group allow to perform a wide spectra of the transformations in the radical of N-protected hydroxylamine derivatives. This is essential for synthetic strategies consisting in the introduction of N-protected aminooxy group at one of the first steps of synthesis and subsequent transformations of the radical. The inhibitory effect of one of the newly synthesized compound, 1-guanidinooxy-3-aminopropane (GAPA), was compared with that of well-known inhibitors of ornithine decarboxylase namely, α-difluoromethylornithine (DFMO) and 1-aminooxy-3-aminopropane (APA) on Leishmania donovani, a protozoan parasite that causes visceral leishmaniasis. GAPA, on the contrary with APA and DFMO, in micromolar concentrations, inhibited the growth of both amastigotes and promastigotes of sodium antimony gluconate-resistant forms of L. donovani. Springer-Verlag 2009.
- Khomutov, Maxim A.,Mandal, Swati,Weisell, Janne,Saxena, Neiha,Simonian, Alina R.,Vepsalainen, Jouko,Madhubala, Rentala,Kochetkov, Sergey N.
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scheme or table
p. 509 - 517
(2010/11/05)
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- HETEROCYCLIC NON-PEPTIDE GNRH ANTAGONISTS
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A compound of formula (I): wherein either B is absent and A and Z are the same or different and are each hydrogen, halogen, alkyl, hydroxy, alkoxy,-CN,-C(Rc)2OH,-N(Rd)C(=X)Rc,-C(=X)N(Rc)(Rd),-S(O)m-Rc,-N(Rc)(Rd)S(O)2,-S(O)2N(R c)(Rd),-N(Re)2, aryl optionally substituted with Ra or-O-aryl optionally substituted with Ra; or B is present and is-(CH2)n-,-C(Rb)2-or-O-, or B taken together with A or Z can be-C=C(Rb)-,-C(Rb)=C-,-CH2-CH(R b)-or-CH(Rb)-CH2-; D is-O-or-S(O) m,-; E is a bond or is-(CH2)n-,-N(R d)-,-(CH2)nN(Rd)-or-N(R d)(CH2)n-; F is-C(=X)-; G is-(CH2 )n-,-N(Rd)-,-(CH2)nN(R d)-or-N(Rd)(CH2)n; J is a bond,-O-,-N(RC)C(=X)-,-C(=X)N(Rc)-,-S(O)m,-,-N(Rc)S(O)m-,-S(O)nN(Rc)-,-N(Re)-or-N(Rg)(Rh); K is a bond, alkylene, cycloalkylene, cycloalkenylene, arylene, heterocycloalkylene, heterocycloalkylene or heteroarylene; and L is hydrogen or a terminal group; has therapeutic utility.
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Page/Page column 70
(2008/06/13)
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- Process for preparation of oxyglutaric acid ester derivatives
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A process for preparing an oxyglutaric acid ester derivative of the formula: STR1 in which each of R1 and R2 is C1-5 alkoxy, C1-7 aralkyloxy, C7-9 halogenated aralkyloxy or phenyl, R4 is a hydroxyl-protecting group, and R5 is C1-10 alkyl which may have a substituent, comprises the steps of reacting a methyl phosphonate derivative or methyl phosphine oxide derivative with an oxyglutaric acid mono-ester to give a reaction product which comprises an oxyglutaric acid derivative having a phosphorus-containing group and a pentenedioic acid mono-ester (by-product), removing the pendenedioic acid mono-ester from the reaction product to isolate the oxyglutaric acid derivative, and converting the isolated oxyglutaric acid derivative into the oxyglutaric acid ester derivative. A process for obtaining an optically active oxyglutaric acid ester derivative is also disclosed.
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- Sulphonate Esters as Sources of Sulphonyl Radicals; Ring-closure Reactions of Alk-4- and -5-enesulphonyl Radicals
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Alkyl alkanesulphonates and arenesulphonates were found to be useful sources of sulphonyl radicals, particularly for spectroscopic work, when treated with organotin or organosilyl radicals.Allyl, propynyl and penta-2,4-dienyl methanesulphonates gave, however, allyl, propynyl and pentadienyl radicals, respectively.Sulphonyl radicals generated in this way added efficiently to alk-1-enes with electron-releasing substituents, and the EPR spectra of the adduct radicals were recorded.A variety of radical initiation systems were tried on pent-4-enesulphonyl chloride.The pent-4-enesulphonyl radical cyclised mainly in the endo mode to give the six-membered-ring sulphone.Similarly, the hex-5-enesulphonyl radical cyclised to give thiepane 1,1-dioxide, with a seven-membered ring.The cyclohex-2-enylethanesulphonyl radical cyclised mainly in the exo mode to give 2-chloro-9-thiabicyclononane 9,9-dioxide.The mechanisms of these reactions are discussed.
- Culshaw, Peter N.,Walton, John C.
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p. 1201 - 1208
(2007/10/02)
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- GENERATION OF SULPHONYL RADICALS FROM SULPHONATE ESTERS
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Alkane alkylsulphonates and arylsulphonates are useful sources of sulphonyl radicals on treatment with organotin radicals.EPR spectra of the adduct radicals from CH3SO2* and alkenes containing donor substituents were observed.
- Culshaw, Peter N.,Walton, John C.
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p. 2457 - 2460
(2007/10/02)
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- REACTION OF PROPOSED PHOSPHOROTHIOLATE S-OXIDE INTERMEDIATES WITH ALCOHOLS
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S-Oxide 2 is an extremely reactive intermediate.Its phosphorylation vs rearrangement rates, strongly depend upon the nature of the nucleophile.
- Segall, Yoffi,Casida, John E.
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p. 209 - 212
(2007/10/02)
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- COORDINATION AND CATALYTIC REACTIONS OF UNSATURATED COMPOUNDS: IV.* INTERPRETATION OF THE MECHANISM OF EPOXIDATION OF ETHYLENE BY SULFUR DIOXIDE
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Sulfur dioxide reacts with ethylene (but not with higher 1-alkenes) under conditions of heterogeneous catalysis at 300-400 deg C to form ethylene oxide and sulfur together with other products.The epoxidation evidently results from complex formation between the ethylene, sulfur dioxide, and catalyst with subsequent colligation of the C-S bonds, ring enlargement through insertion of an oxygen atom at one of these bonds, and elimination of SO from the unstable cyclic sulfinate.Elemental sulfur is formed in all the secondary transformations (during the decomposition of SO and the reduction of SO2 by the oxirane).
- Devekki, A. V.,Koshelev, Yu. V.,Malov, Yu. I.
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p. 829 - 834
(2007/10/02)
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