Showing papers on "Norbornadiene published in 1978"

Preparation of arylplatinum(II) complexes. The interaction of dichloro-(η-cyclo-octa-1,5-diene)platinum(II) and aryltrimethylstannanes

Abstract: One or both chloride ligands of [Pt(cod)Cl2](cod = cyclo-octa-1,5-diene) can be readily and selectively replaced by aryl groups by treatment of the complex with aryltrimethylstannanes in dichloromethane or sym-tetrachioroethane. Use of 1 mol of SnMe3R usually gives the monoaryl complexes in high yield [e.g. R = 2-furyl, 2-thienyl, benzofuran-2-yl, 2-benzothienyl, 1,2-dihydrobenzocyclobuten-3-yl, or C6H4X (X = H, p-MeO, p-Cl, p-F, p-Me3Si, or p-Me)], but for R =η6-p-MeC6H4Cr(CO)3 the diaryl complex is formed. Use of 2 mol of SnMe3R gives the diaryl complexes in good yield [e.g. R as above; plus C6H4X (X =o-MeO, m-MeO, m-F3C, p-Br, m-F, m-Cl, and p-O2N)], but, for steric reasons, with R = C6H2Me3-2,4,6 only the monoaryl complex is formed. The reactivity of the SnMe3R compounds generally parallels the ease of electrophilic substitution at the corresponding R–H bonds. The arylation method has substantial advantages over those using aryl Grignard or lithium reagents. Aryl compounds, MMe3R, of other Group 4 metals undergo analogous reactions, the reactivity decreasing in the sequence (M =) Pb > Sn Ge > Si. While mixed diaryl complexes can sometimes be made in good yield {e.g.[Pt(cod)-(2-C4H3S)(2-C4H3O)] from [Pt(cod)(2-C4H3S)Cl] and SnMe,(2-C4H3O)}, such preparations can be complicated by exchange of aryl groups between platinum centres; e.g.(i) reaction of [Pt(cod)(2-C4H3S)2] with [Pt(cod)Cl2] followed by addition of 1,2-bis(diphenylphosphino)ethane (dppe) gives [Pt(2-C4H3S)Cl(dppe)] in ca. 100% yield, (ii)[Pt(cod)(2-C8H5O)2] and [Pt(cod)(C6H4Cl-m)2] similarly give some [Pt(2-C8H5O)(C6H4Cl-m)(dppe)], and (iii)[Pt(cod)(3-C8H7)Cl] and SnMe3(C6H4Me-p) similarly give some [Pt(3-C8H7)2(dppe)] and [Pt(C6H4Me-p)2-(dppe)](3-C8H7= 1,2-dihydrobenzocyclobuten-3-yl). The olefin ligand is readily displaced from the aryl com-plexes by neutral ligands, and a wide range of [PtR(Cl)L2] and [PtR2L2] complexes with L =½ dppe or PPh3 have been made. The i.r. and 1H, 13C-{1H}, and 31P-{1H} n.m.r. spectra of the products are discussed. For cis-[ Pt(C6H4X-p)2(PPh3)2] complexes the values of 1J(Pt–P) show a good correlation with σI constants. The norbornadiene (nbd) complex [Pt(nbd)Cl2] reacts with SnMe3(2-C4H3O) to give [Pt(2-C4H3O)(nbd)Cl] in 91% yield, but the corresponding palladium complex [Pd(nbd)Cl2] reacts with SnMe3R (R = C6H4OMe-p or C6H4Me-p) to give a dimeric chloride-bridged complex in which the aryl group is attached to the organic ligand.

Schiff-base complexes of ruthenium(II)

Abstract: The interaction of dichlorotris(triphenylphosphine)ruthenium(II) with the sodium salts of various Schiff bases leads to complexes of the type trans-RuL(PPh3)2 for the quadridentate bifunctional ligands and RuL2(PPh3)2 for the bifunctional ligands.Interaction of the chloro-carbonyls, {Ru(CO)2Cl2}n or {Ru(CO)3Cl2}3, with the sodium salt of NN′-ethylenebis-(salicylideneimine), (sal2enH2), yields the pale yellow complex cis-Ru(sal2en)(CO)2.Interaction of the bicyclo[2.2.1]hepta-2,5-diene (norbornadiene) complex {Ru(nbd)Cl2}n with Na2(sal2en) yields Ru(sal2en)(nbd) which has a non-planar ligand structure.I.r. and 1H and 31P n.m.r. spectra of the various complexes are given and structures for the compounds proposed.

Pentamethylcyclopentadienyl-rhodium and -iridium complexes. Part 17. Complexes with sulphur-containing ligands

Abstract: Preparations and properties of the following η5-pentamethylcyclopentadienyl-rhodium and -iridium complexes are reported: [{Rh(C5Me5)}2Cl4(SMe2)], [Rh(C5Me5)(SMe2)3][PF6]2, [Rh(C5Me5)(MeCN)(dithian)][PF6]2, [{Rh-(C5Me5)}2(SS)Cl4](SS = 1,4-dithian, 2,5-dithiahexane), [Rh(C5Me5)(2,5-dithiahexane)2][PF6]2[Rh(C5Me5)-Cl(SR)]n(R = Me, Ph, and PhCH2), [Rh(C5Me5)Cl(S2CNEt2)], [Rh(C5Me5)(S2CNMe2)2], [Rh(C5Me5)-(S2CMe)2], [Rh(C5Me5){S2C2(CN)2}], [{Rh(C5Me5)(3,4-S2C6H3Me)}2], [Ir(C5Me5)(S2CNMe2)2], and [Ir-(C5Me5){S2C2(CN)2}]. The complexes [Rh(C5Me5)(S2CNMe2)2], [Rh(C5Me5)(S2CMe)2], and [Ir(C5Me5)-(S2CNMe2)2] have one uni- and one bi-dentate dithio-ligand.A range of RhI and PdII 1,4-dithian (dt) complexes have also been prepared including [{RhCl(dt)n}]-[{PdX2(dt)}n](X = Cl or Br), [{RhL2(dt)}n][PF6][n= 2, L = PPh3, P(OPh)3; n= 1, L2= cyclo-octa-l,5-diene or norbornadiene] and [Pd(L)(dt)][PF6](L =η32-methylallyl and η3-1-phenylallyl). The poisoning of the [{Rh(C5Me5)Cl2}2]-catalysed olefin hydrogenation by S-containing ligands is contrasted with the ability of some of the above sulphur complexes to catalyse olefin hydrogenation under certain conditions.

Heterocyclic polyfluoro-compounds. Part 26. Synthesis of 3,6-bis-trifluoromethyl-pyridazines and -dihydropyridazines

Abstract: Bistrifluoromethyl-s-tetrazine reacts with styrene to yield 4-phenyl-3,6-bistrifluoromethyl-1,4-dihydropyridazine, with cyclohexene to give 3,8-bistrifluoromethyl-1,3a,4,5,6,7-hexahydrophthalazine, with 2,3-dimethylbut-2-ene to yield 4,4,5,5-tetramethyl-3,6-bistrifluoromethyl-4,5-dihydropyridazine and with norbornadiene to give, it is tentatively proposed, 2,5-bistrifluoromethyl-3,4-diazabicyclo[4.3.0]nona-1,4,8-triene, plus 3,6-bistrifluoromethyl-pyridazine. The last compound is formed by reaction of the tetrazine with acetylene, and 4-methyl- and 4,5-bistrimethylstannyl-3,6-bistrifluoromethyl-pyridazines are formed by reaction with propyne and with bistrimethylstannylacetylene, respectively.Reaction of the tin compound with iodine and with chlorine yields 4,5-di-iodo- and -dichloro-3,6-bistrifluoro-methylpyridazine, respectively, and the latter compound yields perfluoro-3,6-dimethylpyridazine with potassium fluoride.Perfluoro-3,6-dimethylpyridazine rearranges photochemically in the vapour phase into perfluoro-2,5-dimethylpyrazine.

Tetramethylthiophen complexes of rhodium, iridium, palladium, and ruthenium

Abstract: New tetramethylthiophen (tmt) complexes, [M(η5-C5Me5)(tmt)][PF6]2(M = Rh or Ir), [Rh(diene)(tmt)][PF6](diene = cycle-octa-1,5-diene or norbornadiene), [Ru(p-cymene)(tmt)][PF6]2, [Pd(η3-2-MeC3H4)(tmt)2][PF4], and [Pd(tmt)Cl2] have been prepared: the Rh, Ir, and Ru complexes all contain η5-bonded tmt but the two Pd complexes (which were only partially characterised) contain S- and, possibly, η4-bonded tmt respectively. The 2,5-dimethylthiophen (dmt) complexes, [Ir(η5-C5Me5)(dmt)][PF6]2 and [Rh(cod)(dmt)][PF6] were also prepared. The activity of these compounds as hydrogenation catalysts is discussed.

Selective homo-Diels–Alder addition of acetylenic hydrocarbons to norbornadiene catalysed by a cobalt complex

Abstract: A cobalt complex, formed by reducing [Co(acac)3](Hacac = acetylacetone) with diethyl-aluminium chloride in the presence of the bidentate ligand bis(1,2-diphenylphosphino)ethane, is an active catalyst for the selective [2+2+2] cycloaddition of acetylenic hydrocarbons RCCH (R = alkyl, H, or aryl) to norbornadiene.

Stereoselective cobalt-catalysed [2 + 2 + 2] cross-addition of norbornadiene and norbornene

Abstract: A cobalt complex, formed by reducing [Co(acac)3](Hacac = acetylacetone) with diethyl-aluminium chloride in the presence of the bidentate ligand bis(1,2-diphenylphosphino)ethane, is an active catalyst for the stereoselective [2 + 2 + 2] cycloaddition of norbornene to norbornadiene.

Catalyst for asymmetric hydrogenation

Abstract: PURPOSE: To obtain a catalyst for asymmetric hydrogenation useful for the synthesis of optical active amino acid by coordinating a phosphine derivative having the specific formal with rhodium in a rhodium complex catalyst in which a chiral phosphine is a ligand. CONSTITUTION: In a catalyst composed of rhodium complex in which a chiral phosphine is a ligand, as phosphine an optical active phosphine derivative having the formula I (wherein R 1 and R 2 are alkyl, aryl or aralkyl group, and naphthalene rings may having an ortho-substituent such as an alkyl, halogen, and amino group with respect to the phosphorus substituent) is coordinated with rhodium metal. Examples of rhodium compounds include Rh (acetylacetonato) (1.5-cyclooctadiene), Rh (acetylacetonato) (norbornadiene) and the like. COPYRIGHT: (C)1980,JPO&Japio

Eisenpentacarbonyl‐induzierte Reaktionen von Norbornadien und substituierten Olefinen

Abstract: Iron Pentacarbonyl Induced Reactions of Norbornadiene and Substituted Olefins The photochemical reaction of norbornadiene and α, β-unsaturated nitriles, esters and amides in the presence of Fe(CO)5 was studied. Nitriles furnished the dinorbornenyl ketones 2a-c (Scheme 1). Esters led to an addition of a norbornene moiety to the double bond giving the substituted α, β-unsaturated esters 10a and 10b (Scheme 5). Methacrylamide and methyl β-aminocrotonate gave the cyclopentanone derivatives 14 and 17, respectively (Schemes 7 and 8). The reaction was in all cases highly stereoselective with general exo-substitution on the norbornadiene. The attack on the unsymmetric olefins occurred regiospecifically at that point of the double bond which was furthest away from the functional group. A plausible mechanism for these reactions is suggested in Schemes10and11.

Binuclear diaryltriazenido- and aryl(1-aryliminoethyl)amido-complexes of rhodium

Abstract: The complex [{RhCl(CO)2}2] reacts with Na[RNNNR](R = C6H4Me-p) or Li[RNC(Me)NR](R = Ph or C6H4Me-p) to give [{Rh(µ-L)(CO)2}2][L = RNNNR (1) or RNC(Me)NR (2)]. Complexes (1) and (2) undergo substitution reactions with PPh3, to yield [{Rh(RNNNR)(CO)(PPh3)}2](3; R = C6H4Me-p) and [Rh2{RNC(Me)NR}2(CO)3(PPh3)](4; R = Ph) respectively, and oxidative addition with I2 yielding [{Rhl(µ-L)(CO)2}2](5). With cyclo-octa-1,5-diene (cod) or norbornadiene (nbd), (1) affords [Rh2(RNNNR)2(CO)2(cod)](6) and [{Rh(RNNNR)(diene)}n](7; diene = cod or nbd).

Photochemical and thermal reactions of heterocycles. Part 2. Photolysis of 2,3-diphenylnaphthoquinone 2,3-epoxide: trapping of a cyclic carbonyl ylide and photoisomerisation

Abstract: Photolysis of 2,3-diphenylnaphthoquinone epoxide (1) caused epoxy-carbon–carbon bond cleavage to form a cyclic carbonyl ylide (4), which was trapped by dipolarophiles. The norbornadiene primary adduct (3) underwent further photochemical isomerisation, via methylenephthalide derivatives (5), to spiro[oxetan-phthalide] derivatives (7), which reverted thermally to methylenephthalides (5). Thermal fragmentation of an oxabicycloheptadiene adduct (18a) gave a formal acetylene adduct (11) and a furan (21). Carbon-13 n.m.r. spectroscopy was useful in establishing the structures of the products. Photolysis of the epoxide (1) in the absence of a dipolarophile gave 3-(α-benzoylbenzylidene)phthalides (24).

Plasticized sulfur with improved stability

Abstract: Sulfur is plasticized by the addition of 1,4,4a,5,8,8a-hexahydro-1,4,5,8-exo,endo-dimethanonaphthalene which is an adduct of norbornadiene and cyclopentadiene.

Isomerization of endo-endo hexacyclic olefinic dimer of norbornadiene

Abstract: The endo-endo olefinic hexacyclic dimer of 2,5-norbornadiene is isomerized using an acidic alumina catalyst. The isomerization temperatures ranges from between about an ambient temperature to about 300° C. The isomerized product, after hydrogenation, can be used as a high density missile fuel.

Determination of Some Color Components Present in Petroleum Resin

Abstract: In a previous report, it was found that some of the color components in the starting material of petroleum resin were cyclopentadiene, methylcyclopentadiene, and their dimers. In the present study, other color components than those mentioned above and the cause of coloring petroleum resin by cyclopentadiene and methyl derivative were investigated. Norbornadiene and ethylidene norbornene were found also to be color components, and the structures of some conjugated systems which color the petroleum resin were inferred from the data of ESR spectra.

Codimer of norbornadiene and cyclohexadiene

Abstract: Novel codimer (I) of norbornadiene and 1,3-cyclohexadiene and its hydrogenated derivative (II), having the following structures: ##STR1## and processes for preparing both are disclosed. Product (II) can be used as a high energy fuel. Process for codimer I involves use of three component homogeneous catalytic system of cobaltic or cobaltous acetylacetonate, 1,2-bisdiphenylphosphino ethane and one of three alkyl aluminum chlorides.

Improved process for producing ringgopening polymer

Abstract: PURPOSE:The ring-opening polymerization of norbornene or norbornadiene derivative is conducted in the presence of a specific catalyst.

Process for the production of exo-exo hexacyclic dimer of norbornadiene

Abstract: Process involves the continuous production of exo-exo stereoisomer of the hexacyclic dimer of norbornadiene using a three component catalytic system of diethylaluminum chloride, ferric acetylacetonate, and bis(1,2-diphenylphosphino)ethane. Temperature range of reaction is about 100-220 DEG F, and residence time is about 1-10 hours. Process further involves taking a product stream, along with any catalyst and other materials and treating it to deactivate the catalyst; then separating the desired exo-exo dimer by various means at a temperature below about 500 DEG F to avoid decomposition of iron salts. Unreacted norbornadiene in the process is recycled.

Catalytic codimerization of norbornadiene with norbornene

Abstract: Norbornadiene and nobornene are catalytically codimerized to the saturated exo-exo hexacyclic dimer of norbornadiene. Used is a three-component homogeneous catalytic system consisting of cobaltic or cobaltous acetylacetonate, 1,2-bisdiphenylphosphino ethane and an alkyl aluminum chloride. Resulting dimer can be used as a component of high energy fuel.