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Propane, reaction

Catalysts of the Co(salen) family incorporating chiral centers on the ligand backbone are useful in asymmetric synthesis and the field has been reviewed.1377,1378 In two examples, the hydroxy-lation reaction (Equation (14)) involving (269) proceeds with 38% ee,1379 whereas the cyclo-propanation reaction with (271) (Equation (15)) proceeds with 75% ee and with 95 5 trans cis.1380 A Co(V) salen carbenoid intermediate has been suggested in these reactions. [Pg.117]

Schultz and Linden Ind. Eng. Chem. Process Design and Development, 1 (111), 1962] have studied the hydrogenolysis of low molecular weight paraffins in a tubular flow reactor. The kinetics of the propane reaction may be assumed to be first-order in propane in the regime of interest. From the data below determine the reaction rate constants at the indicated temperatures and the activation energy of the reaction. [Pg.308]

From an historical point of view, the earliest indication of spin-selective reactivity of carbenes was exhibited by the stereochemistry of the cyclo-propanation reaction. The Skell Hypothesis (Skell and Woodworth, 1956) suggests that a spin-prohibition requires the addition of a triplet carbene to an olefin to occur in at least two steps. In turn, the obligatory formation of an... [Pg.329]

Katranas,T.K.,Triantafyllidis, K.S., Vlessidis, A.G., and Evmiridis, N.P. (2007) Propane reactions over faujasite structure zeolites type-X and USY effect of zeolite silica over alumina ratio, strength of acidity and kind of exchanged metal ion. Catal. Lett., 118,79-85. [Pg.399]

Propane reaction. In a series of experiments propane (760 torr) reacted at 773 K over H-ZSM-5 (Si/Al = 15) and H-ZSM-5 modified with Ga or Pt. The conversion of propane was maintained at around 30% by adjusting the flow rate between 1 and 10 l.h , higher flow rates being used for the most active catalysts. The catalytic activities for the different solids were normalized to that of H-ZSM-5. The data are summarized in Table 1. It is apparent that the addition of Ga, Pt, Pt-Cu to the H-ZSM-5 zeolite increased its activity for the propane conversion. [Pg.269]

General considerations on the mechanism of C3Hg reaction over HZSM-5 and Ga- HZSH-5. The products obtained from the reaction of C2 C5 alkanes over H-ZSM-5 zeolites were nicely interpreted (3-6) according to the classical carbenlum ion theory and the non-classical theory developed for reactions occurring in superacid media where an alkane is protonated to form the carbocation species. The general scheme proposed for propane reaction over H-ZSM-5 is ... [Pg.275]

The catalytic cycle proposed for the rhodium-porphyrin-based catalyst is shown in Fig. 7.18. In the presence of alkene the rhodium-porphyrin precatalyst is converted to 7.69. Formations of 7.70 and 7.71 are inferred on the basis of NMR and other spectroscopic data. Reaction of alkene with 7.71 gives the cyclopropanated product and regenerates 7.69. As in metathesis reactions, the last step probably involves a metallocyclobutane intermediate that collapses to give the cyclopropane ring and free rhodium-porphyrin complex. This is assumed to be the case for all metal-catalyzed diazo compound-based cyclo-propanation reactions. [Pg.164]

The role of the collisional deactivation of excited sulfur atoms in paraffin reactions (as well as in the COS-olefin systems) has been convincingly demonstrated in separate studies with added inert gases. The data given in Table II show that large excess of CO2 completely suppresses the formation of the propyl mercaptans in the propane reaction by collisional quenching of S( Z)) atoms,... [Pg.153]

The pressure dependence of kg/ku at X = 2288 A. can be accounted for by the observation that at this wavelength small amounts of disulfides are formed in the ethane and propane reactions, which were not taken into consideration evaluating the rate constant values. The disulfide can arise (1) from the secondary photolysis of the mercaptan product when the COS pressure is low, and 2) by cracking of hot RSH molecules at low total pressures. From Table III there appears to be a twofold variation in the value of h/kn for the ethane reaction, in going from low COS and total pressure to high COS and total pressure. [Pg.156]

Finally, the lack of any deuterium isotope effect in the propane reaction would suggest that the insertion reaction is fast and that no significant C—H bond stretching occurs in the transition state. [Pg.165]

Figure 1. Energy profiles of the most important reaction channels in the 0( P) + methane, ethane and propane reactions, (a) H abstraction 0( P) + RH —> OH + R. (b) H elimination 0( P) + RH -> H + RO. (c) C-C breakage 0( P) + R OR + R . The energy scale of (a) is half that of (b) and (c). The energy of the stationary points refers to B3LYP/6-31G calculations. Figure 1. Energy profiles of the most important reaction channels in the 0( P) + methane, ethane and propane reactions, (a) H abstraction 0( P) + RH —> OH + R. (b) H elimination 0( P) + RH -> H + RO. (c) C-C breakage 0( P) + R OR + R . The energy scale of (a) is half that of (b) and (c). The energy of the stationary points refers to B3LYP/6-31G calculations.
Figure 4- Average fractions of energj- in products as a function of collision energj- for the H elimination reaction channel in the O( P) + methane, ethane and propane reactions. Thick lines show average fractions of product translational energy and thin lines are for average fractions of internal cnergv in the oxyradical molecules. Figure 4- Average fractions of energj- in products as a function of collision energj- for the H elimination reaction channel in the O( P) + methane, ethane and propane reactions. Thick lines show average fractions of product translational energy and thin lines are for average fractions of internal cnergv in the oxyradical molecules.
A 1-chloro-l-lithio compound (lithium carbenoid) is likely to be involved in the cyclo-propanation reaction that occurs when hexachlorocyclobutene is treated with butyllithium in the presence of a large excess of an alkene such as (Z)- or ( )-but-2-ene and 2-methylbut-2-ene. The reaction is stereospecific with respect to the alkene double-bond configuration, e.g. formation of 9. ... [Pg.408]

An ester function more remote from the double bond does not influence, generally, the cyclo-propanation reaction, see, for example, ref 289. [Pg.677]

An examination of the nearest consequences of propyl radical transformation in the gas phase indicates that a substantial part of propane reaction proceeds within the above-discussed C3 C2 kinetic scheme. This fact opens up the prospect for the development of a propane oxidation scheme by the stepwise buildup of a C1-C2 joint description. In the course of this procedure special attention should be paid to the execution of the fullness principle. Although, as we mentioned above, in the case of C3+ hydrocarbon oxidation the contribution of several mysterious types of intermediates may substantially increase, the blocks accounting for the elementary reaction of normal species must be described as thoroughly as possible. [Pg.243]

Conversely, for very exothermic reactions, changes in enthalpy of reaction will have little effect on the activation energy, giving unselective reactions. The corresponding fluorination of propane (reaction 3.4) is highly exothermic AH = —159 kJ mol-1 at the 1-position and —173 kJ mol 1 at the 2-position. However, with an early transition state and a very small activation energy for both reactions, there is little difference in rate for attack at the two positions and the reaction is very unselective. [Pg.47]

In close structural analogy to the semicorrinate ligands of 9, the bidendate, chiral C2-symmetric 5-azasemicorrins 10216 and bis(4,5-dihydrooxazol-2-yl)methane systems li,196 217 12,218 219 12a,197 13,220 and I4197a perform exceptionally well in copper-catalyzed enantioselective cyclo-propanation reactions with diazo esters. With 10, 11, and 12 a, the active catalyst is prepared in situ by adding a catalytic amount of a copper(I) salt with a weakly coordinating anion [copper(I) triflate,196,217,219 copper(I) perchlorate197] to the free ligand with the enolizable system 12 (as well as with 12a and 14) it has been prepared by reaction with copper(I) terh butoxide or from the copper(I) bischelate complex by reduction with phenylhydrazine. [Pg.459]


See other pages where Propane, reaction is mentioned: [Pg.13]    [Pg.267]    [Pg.242]    [Pg.599]    [Pg.231]    [Pg.258]    [Pg.271]    [Pg.429]    [Pg.145]    [Pg.32]    [Pg.184]    [Pg.511]    [Pg.608]    [Pg.338]    [Pg.341]    [Pg.343]    [Pg.345]    [Pg.20]    [Pg.459]    [Pg.175]    [Pg.632]    [Pg.608]    [Pg.413]    [Pg.338]    [Pg.345]   
See also in sourсe #XX -- [ Pg.792 , Pg.793 ]

See also in sourсe #XX -- [ Pg.792 , Pg.793 ]




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Carbon dioxide propane chemical reactions

One-pot multicomponent reaction propan-2-amine

Oxygen reaction with propane

Propan-1,2-diol, reaction with

Propanal Wittig reaction

Propanal self-aldol reactions

Propanal, 2-cyclohexylaldol reaction

Propanal, 2-cyclohexylaldol reaction simple diastereoselection

Propanal, 2-phenyladdition reactions with bromomethylmagnesium

Propanal, 2-phenyladdition reactions with bromomethylmagnesium Lewis acids

Propanal, 2-phenyladdition reactions with bromomethylmagnesium diastereoselectivity

Propanal, 2-phenylaldol reaction

Propanal, 2-phenylaldol reaction simple diastereoselection

Propanal, 2-phenylaldol reaction stereoselection

Propane Friedel-Crafts reaction

Propane ODH reactions

Propane combustion reaction

Propane reaction with hydroxyl radicals

Propane reaction with oxygen atoms

Propane reaction with rhenium

Propane reactions with cyclopentadienyl

Propane, l-chloro-2-phenylbenzene alkylation Friedel-Crafts reaction

Propane, reaction with deuterium

Propane, reactions with

Propane-1,3-diols, reaction with diacetylene

Propane-1,3-dione, 1,3-diphenylKnoevenagel reaction

Propane-1,3-dithiol, reaction with aldehydes

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