Methine (CH) Transfer via a Chlorine Atom Abstraction/Benzene-Elimination Strategy:  Molybdenum Methylidyne Synthesis and Elaboration to a Phosphaisocyanide Complex

2002 ◽  
Vol 124 (11) ◽  
pp. 2412-2413 ◽  
Author(s):  
Theodor Agapie ◽  
Paula L. Diaconescu ◽  
Christopher C. Cummins
1987 ◽  
Vol 22 (3) ◽  
pp. 427-436 ◽  
Author(s):  
S.E. Hrudey ◽  
E. Knettig ◽  
P.M. Fedorak ◽  
S.A. Daignault

Abstract Rapid and preferential dechlorination of the ortho chlorine from 2,6-, 2,4- and 2,3- dichlorophenol substrates was observed in semi-continuous cultures inoculated with 50% unacclimated anaerobic sludge. The rate of further dechlorination depended on the position of the second chlorine atom. The dechlorination rates for the second chlorine ranked ortho > para > meta. Complete mineralization to methane was only observed in cultures fed 2,6-dichlorophenol. Addition of activated carbon to the anaerobic cultures showed some benefit to the degradation process.


2020 ◽  
Vol 24 (15) ◽  
pp. 1663-1668
Author(s):  
Dmitriy Yurievich Direnko ◽  
Boris Ivanovich Drevko ◽  
Yaroslav Borisovich Drevko

We have explored the reactions of tetrahydro-4H-selenochromenes in the presence of phosphoric pentachloride, and synthesized new condensate aroylbenzoselenophenes. During the reactions, tetrahydro-4H-selenochromenes with phosphoric pentachloride underwent oxidative aromatization and nucleophilic substitution for a chlorine atom of one of the protons in the alicyclic fragment. Also, the narrowing of the heterocyclic fragment occurred as in synthesized selenium-containing compounds earlier transformed into the corresponding condensate aroylbenzoselenophenes.


1983 ◽  
Vol 48 (12) ◽  
pp. 3426-3432 ◽  
Author(s):  
Dušan Koščík ◽  
Pavol Kristian ◽  
Ondrej Forgáč

New synthesis of pyrido[3,4-e]-1,3-thiazines consisting in reaction of 2,6-dimethyl-4-chloronicotinoyl isothiocyanate with primary or secondary amines, or with benzaldehyde phenylhydrazone, is described. High reactivity of the chlorine atom does not allow isolation of the corresponding thioureas, arising as intermediates, except in the case of the benzylamino derivative. Structure of the products was unequivocally confirmed by their spectral data (IR, UV, 1H NMR, 13C NMR and mass spectra). The synthesized derivatives do not undergo the Dimroth rearrangement.


2006 ◽  
Vol 61 (10) ◽  
pp. 1261-1274 ◽  
Author(s):  
Florian Armbruster ◽  
Nina Armbruster ◽  
Uwe Klingebiel ◽  
Mathias Noltemeyer ◽  
Stefan Schmatz

The results of quantum chemical calculations on lithium ketazides suggest mainly four isomeric structures with different modes of lithium coordination (A-D). A monolithium ketazide thf-adduct (1) was isolated supporting the results of the quantum chemical calculations. In reactions of the lithiated di(tert-butyl-methyl)ketazine with BCl3 and Cl2BPh, 1,2-aza-azonia-3-borata-cyclopent-5-enes (2, 3) were isolated. Substitution of a chlorine atom of 2 and 3 with t-BuLi leads to the formation of derivatives 4 and 5. HCl elimination from 2 with Et3N gives - via a diazaboracyclopentene (6) - a bicyclus 7. In the reaction of the dilithiated ketazine with F2BN(SiMe3)2, the diaza-boracyclopentene 8 is obtained while with Cl4Si, F3SiN(SiMe3)2, and Cl2SiMe2 the diazasilacyclopentenes 9 - 11 are generated. SiF4 reacts with the dilithium ketazide to give a spirocyclus (12). The monolithium ketazide and Cl2SiMe2 react at 30 °C to give a four-membered ring isomer of the substitution product which is formed via a 1,3-chlorine shift from silicon to carbon (13). A tetrameric silanolate was isolated as a by-product in this reaction. It gives evidence for the structure of lithium ketazide A. Crystal structures of 5, 7, 10, and 14 are reported.


1965 ◽  
Vol 18 (3) ◽  
pp. 271 ◽  
Author(s):  
IR Anderson ◽  
JC Sheldon

The new compounds, K6Mo3IICl12; (NH4)7Mo3IICl13.H2O; and Cs6Mo4Cl16 (containing molybdenum in oxidation state +2.5) have been precipitated by the appropriate cation from solutions of molybdenum(II) acetate in 12M hydrochloric acid. The absorption spectra of potassium and ammonium salts are similar in the solid state and solution. Since the compounds are strong reducing agents and short-lived in solution, their formulation as a staphylonuclear (i.e. metal-clustered) trimer or tetramer rests on their diamagnetism, stoicheiometry, and spectral similarities. It is proposed that the chloromolybdates adopt entirely novel, compact polymers by stacking the chlorine atoms into "close packed" layers. The Mo3Cl13 group consists of two layers of chlorine atoms (seven and six) generating three octahedral locations for the molybdenum atoms at the corners of a regular triangle. The Mo3Cl12 group is similar but deficient in one chlorine atom. The Mo4Cl16 group is related to Mo3Cl13 and consists of three layers of chlorine atoms (seven, six, and three) providing four octahedral locations for the molybdenum atoms at the corners of a tetrahedron.


2012 ◽  
Vol 455-456 ◽  
pp. 25-28 ◽  
Author(s):  
Zhi Peng Tong ◽  
Gang Liu ◽  
Shi Qiang Cui

A new unsymmetrical photochromic diarylethene 1-(2,4-dimethyl-3-isoxazol)-2-[2-methyl-5-(2-chlorophenyl) -3-thienyl] perfluorocyclopentene (1a) has been synthesized. Its photochromic properties in solution and PMMA film were investigated. Diarylethene 1a changed the color from colorless to red upon irradiation with 297 nm UV light, in which absorption maxima were observed at 515 nm in hexane and at 526 nm in PMMA film, The results demonstrated that it can be potentially used as polarization holographic optical recording medium.


1984 ◽  
Vol 53 (5) ◽  
pp. 1081-1089 ◽  
Author(s):  
S.M.A. Hoffmann ◽  
D.J. Smith ◽  
T.A. Steele ◽  
R. Grice

2006 ◽  
Vol 61 (11-12) ◽  
pp. 809-814 ◽  
Author(s):  
Alina Świzdor ◽  
Teresa Kołek ◽  
Anna Szpineter

Keywords The course of transformations of the pharmacological steroids: testosterone propionate, 4-chlorotestosterone acetate, 17β-estradiol diacetate and their parent alcohols in Fusarium culmorum AM282 culture was compared. The results show that this microorganism is capable of regioselective hydrolysis of ester bonds. Only 4-ene-3-oxo steroid esters were hydrolyzed at C-17. 17β-Estradiol diacetate underwent regioselective hydrolysis at C-3 and as a result, estrone - the main metabolite of estradiol - was absent in the reaction mixture. The alcohols resulting from the hydrolysis underwent oxidation at C-17 and hydroxylation. The same products (6β- and 15α-hydroxy derivatives) as from testosterone were formed by transformation of testosterone propionate, but the quantitative composition of the mixtures obtained after transformations of both substrates showed differences. The 15α-hydroxy deriv­atives were obtained from the ester in considerably higher yield than from the parent alcohol. The presence of the chlorine atom at C-4 markedly reduced 17β-saponification in 4-chloro- testosterone acetate. Only 3β,15α-dihydroxy-4α-chloro-5α-androstan-17-one (the main prod­uct of transformation of 4-chlorotestosterone) was identified in the reaction mixture. 6β- Hydroxy-4-chloroandrostenedione, which was formed from 4-chlorotestosterone, was |not de­tected in the extract obtained after conversion of its ester.


2006 ◽  
Vol 8 (25) ◽  
pp. 5757-5760 ◽  
Author(s):  
Dan Yang ◽  
Yi-Long Yan ◽  
Bao-Fu Zheng ◽  
Qiang Gao ◽  
Nian-Yong Zhu

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