590-21-6Relevant articles and documents
Molybdenum chloride catalysts for Z-selective olefin metathesis reactions
Koh, Ming Joo,Nguyen, Thach T.,Lam, Jonathan K.,Torker, Sebastian,Hyvl, Jakub,Schrock, Richard R.,Hoveyda, Amir H.
, p. 80 - 85 (2017/04/01)
The development of catalyst-controlled stereoselective olefin metathesis processes has been a pivotal recent advance in chemistry. The incorporation of appropriate ligands within complexes based on molybdenum, tungsten and ruthenium has led to reactivity and selectivity levels that were previously inaccessible. Here we show that molybdenum monoaryloxide chloride complexes furnish higher-energy (Z) isomers of trifluoromethyl-substituted alkenes through cross-metathesis reactions with the commercially available, inexpensive and typically inert Z-1,1,1,4,4,4-hexafluoro-2-butene. Furthermore, otherwise inefficient and non-stereoselective transformations with Z-1,2-dichloroethene and 1,2-dibromoethene can be effected with substantially improved efficiency and Z selectivity. The use of such molybdenum monoaryloxide chloride complexes enables the synthesis of representative biologically active molecules and trifluoromethyl analogues of medicinally relevant compounds. The origins of the activity and selectivity levels observed, which contradict previously proposed principles, are elucidated with the aid of density functional theory calculations.
2, 3, 3, 3-tetrafluoropropene method for the synthesis of
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Paragraph 0009; 0020; 0021, (2018/01/19)
The invention discloses a method for synthesizing 2,3,3,3-tetrafluoropropene and belongs to the field of organic synthesis. The method comprises the following steps: (1) preparing 2-chloropropene from 1,2-dichloropropane, which serves as a raw material, through continuous catalytic cracking by adopting a fixed bed in the presence of beta-zeolite, which serves as a catalyst; (2) selectively chlorinating 2-chloropropene with chlorine gas under the catalysis of ferric chloride, so as to prepare 2,3,3,3-tetrachloropropylene; and (3) fluorating 2,3,3,3-tetrachloropropylene with hydrofluoric acid under the catalysis of SbF3 or SbF5, thereby obtaining 2,3,3,3-tetrafluoropropene. The synthesis route has the advantages that the source of raw materials is wide, the cost is low, and the product yield is high; and the obtained product can serve as an automotive air conditioning refrigerant and has a positive significance in reduction of greenhouse effect.
Study of the catalytic dehydrochlorination of 1,2-dichloropropane
Nadzhafov, Dzh Yu
scheme or table, p. 1532 - 1540 (2012/01/14)
Catalytic dehydrochlorination of 1,2-dichloropropane in the presence of γ-Al2O3, CaX, and haydite was studied. A relationship between the catalytic activity and acidity of the catalysts under study was revealed.
Flash vacuum pyrolysis over magnesium. Part 1 - Pyrolysis of benzylic, other aryl/alkyl and aliphatic halides
Aitken, R. Alan,Hodgson, Philip K.G.,Morrison, John J.,Oyewale, Adebayo O.
, p. 402 - 415 (2007/10/03)
Flash vacuum pyrolysis over a bed of freshly sublimed magnesium on glass wool results in efficient coupling of benzyl halides to give the corresponding bibenzyls. Where an ortho halogen substituent is present further dehalogenation gives some dihydroanthracene and anthracene. Efficient coupling is also observed for halomethylnaphthalenes and halodiphenylmethanes while chlorotriphenylmethane gives 4,4′-bis(diphenylmethyl)biphenyl. By using α,α′-dihalo-o-xylenes, benzocyclobutenes are obtained in good yield, while the isomeric α,α′-dihalo-p-xylenes give a range of high thermal stability polymers by polymerisation of the initially formed p-xylylenes. Other haloalkylbenzenes undergo largely dehydrohalogenation where this is possible, in some cases resulting in cyclisation. Deoxygenation is also observed with haloalkyl phenyl ketones to give phenylalkynes as well as other products. With simple alkyl halides there is efficient elimination of HCl or HBr to give alkenes. For aliphatic dihalides this also occurs to give dienes but there is also cyclisation to give cycloalkanes and dehalogenation with hydrogen atom transfer to give alkenes in some cases. For 5-bromopent-1-ene the products are those expected from a radical pathway but for 6-bromohex-1-ene they are clearly not. For 2,2-dichloropropane and 1,1-dichloropropane elimination of HCl occurs but for 1,1-dichlorobutane, -pentane and -hexane partial hydrolysis followed by elimination of HCl gives E, E-, E,Z- and Z,Z- isomers of the dialk-1-enyl ethers and fully assigned 13C NMR data are presented for these. With 6-chlorohex-1-yne and 7-chlorohept-1-yne there is cyclisation to give methylenecycloalkanes and -cycloalkynes. The behaviour of 1,2-dibromocyclohexane and 1,2-dichlorocyclooctane under these conditions is also examined. Various pieces of evidence are presented that suggest that these processes do not involve generation of free gas-phase radicals but rather surface-adsorbed organometallic species.
KINETICS OF 1,2-DICHLOROPROPANE PYROLYSIS
Solyannikov, V. E.,Bykov, D. E.,Berlin, E. R.,Vartanov, I. A.
, p. 1608 - 1611 (2007/10/03)
Pyrolysis of 1,2-dichloropropane at 480-560 deg C and with a contact time of up to 10 sec has been studied, and kinetic characteristics of the process have been determined.
TWO ROUTES OF PROPENE CONVERSION INTO PERCHLORO DERIVATIVES BY THE ACTION OF HYDROGEN CHLORIDE AND OXYGEN.
Potapov
, p. 1773 - 1774 (2007/10/02)
Destructive catalytic conversions of propene by the action of hydrogen chloride and oxygen are of complex character and may proceed by several routes, depending on the oxygen and hydrogen chloride contents in the reactants. Elucidation of the character of these routes is of practical interest, and is necessary for selection of the process conditions. In view of this , the influence of the hydrogen chloride:propene ration on the process was studied in the ranges from 0 to 6 (contract time 2 sec) and from 6 to 12 (contact time 5 sec) at the constant stoichiometric ratio HCl:O//2 equals 2. The interaction of propene with hydrogen chloride at HCl:C//3H//6 ratios from 6 to 12 (Fig. lb) has certain peculiarities, with chlorinolysis of hexachloropropene. However, at HCl:C//3H//6 ratios from 9 to 10. 5 acrolein is formed and then converted into various compounds with evolution of the corresponding amounts of carbon monoxide. It is shown that the conversions of propene into various compounds proceed by two routes, with intermediate formation of allyl chloride and acrolein.
Thermocatalytic Reactions of Bromochloropropanes
Levanova, S. V.,Rodova, R. M.,Tereshkina, T. P.,Zabrodina, T. I.
, p. 1142 - 1146 (2007/10/02)
The thermodynamic characteristics of the disproportionation and dehydrohalogenation reactions of halogenopropanes (1,2- and 2,2-isomers) have been calculated and tested experimentally.The legitimacy of using the incremental method for the calculation of the thermodynamic functions of bromochloropropanes has been demonstrated.An increase of the length of the hydrocarbon group and the geminal positions of the halogen atoms in the molecule greatly reduce the probability of disproportionation reactions.
Reaction of α,β-Unsaturated Acid Chlorides with Tris(triphenylphosphine)chlororhodium(I): Formation of Phosphonium Salts
Kampmeier, J. A.,Harris, S. H.,Rodehorst, R. M.
, p. 1478 - 1485 (2007/10/02)
The reaction of (E)-cinnamoyl chloride and tris(triphenylphosphine)chlororhodium(I) in equivalent amounts in dichloroethane at 85 deg C gives styryltriphenylphosphonium chloride and bis(triphenylphosphine)chlorocarbonylrhodium in good yields. (E)-2-Butenoyl chloride gives 1-propenyltriphenylphosphonium chloride, and (E)-2-heptenoyl chloride gives a mixture of 1- and 2-hexenyltriphenylphosphonium chlorides. 3-Methyl-2-butenoyl chloride gives only isobutylene.None of these α,β-unsaturated acid chlorides give the expected 1-chloro-1-alkene.Control experiments showed that the phosphonium salts are not formed by secondary reactions.Bis(triphenylphosphine)styryldichlorocarbonylrhodium was shown to be an intermediate in the formation of styryltriphenylphosphonium chloride.A study of the kinetics of decomposition of the intermediate showed that dissociation of chloride ion is the rate-determining step.The observed rate law is -d/dt = kk'-> + k').The significance of these observations for an understanding of the details of the "reductive elimination" reaction is discussed.
