2177-49-3Relevant articles and documents
Synthesis of Pentafulvalene by Oxidative Coupling of Cyclopentadienide with Copper(II) Chloride
Escher, Andre,Rutsch, Werner,Neuenschwander, Markus
, p. 1644 - 1654 (1986)
Starting with a nearly quantitative coupling of cyclononatetraenide 7 to 1,1'-dihydrononafulvalene 8 by means of AgBF4, a simple general synthetic concept for fulvalenes is outlined (Scheme 2), consisting in an oxidative coupling of 'Hueckel anions' like 2 and 7 to 1,1'-dihydrofulvalenes 10 with Ag(I) or Cu(II) salts, followed by deprotonation (->11) and oxidation (->12); it has been realised in the case of pentafulvalene (1; overall yield 61percent; Scheme 3) and 1,2:5,6-dibenzopentafulvalene (18; overall yield 66percent; Scheme 4).NMR-spectroscopic investigations show that 1 is a non-aromatic compound with strongly alternating bond-lengths, its ?-system being even more localised than that of simple pentafulvenes.In fact, 1 is extremely reactive in concentrated solutions above -50 deg C.Besides of polymerisations, Diels-Alder dimerisation 1->19 followed by a rearrangement 19->20 takes place (Scheme 5).
Synthesis of 1,1'-Biindenes and 3,3'-Biindenes
Nicolet, Pierre,Sanchez, Jean-Yves,Benaboura, Ahmed,Abadie, Marc J. M.
, p. 202 - 203 (1987)
1,1'-Biindenes 2, conveniently prepared from indenyllithiums by treatment with copper(II) chloride, are quantitatively isomerized to the corresponding 3,3'-biindenes 3 by heating in triethylamine/pyridine.Both d,l and meso isomers of 2 react to form 3; the rate of reaction of the meso form, however, is substantially faster.
Silver-catalyzed coupling reactions of alkyl halides with indenyllithiums
Someya, Hidenori,Yorimitsu, Hideki,Oshima, Koichiro
scheme or table, p. 5993 - 5999 (2010/09/10)
Coupling reactions of tertiary and secondary alkyl halides with indenyllithiums proceeded effectively in the presence of a catalytic amount of silver bromide to provide tertiary- and secondary-alkyl-substituted indene derivatives in good yields.
Trimethyl phosphite as a trap for alkoxy radicals formed from the ring opening of oxiranylcarbinyl radicals. Conversion to alkenes. Mechanistic applications to the study of C-C versus C-O ring cleavage
Ding, Bangwei,Bentrude, Wesley G.
, p. 3248 - 3259 (2007/10/03)
Trimethyl phosphite, (MeO)3P, is introduced as an efficient and selective trap in oxiranylcarbinyl radical (2) systems, formed from haloepoxides 8-13 under thermal AIBN/n-Bu3SnH conditions at about 80 °C. Initially, the transformations of 8-13, in the absence of phosphite, to allyl alcohol 7 and/or vinyl ether 5 were measured quantitatively (Table 1). Structural variations in the intermediate oxiranylcarbinyl (2), allyloxy (3), and vinyloxycarbinyl (4) radicals involve influences of the thermodynamics and kinetics of the C-O (2 → 3, k1) and C-C (2 → 4, k2) radical scission processes and readily account for the changes in the amounts of product vinyl ether (5) and allyl alcohol (7) formed. Added (MeO)3P is inert to vinyloxycarbinyl radical 4 and selectively and rapidly traps allyloxy radical 3, diverting it to trimethyl phosphate and allyl radical 6. Allyl radicals (6) dimerize or are trapped by n-Bu3SnH to give alkenes, formed from haloepoxides 8, 9, and 13 in 69-95% yields. Intermediate vinyloxycarbinyl radicals (4), in the presence or absence of (MeO)3P, are trapped by n-Bu3SnH to give vinyl ethers (5). The concentrations of (MeO)3P and n-Bu3SnH were varied independently, and the amounts of phosphate, vinyl ether (5), and/or alkene from haloepoxides 10, 11, and 13 were carefully monitored. The results reflect readily understood influences of changes in the structures of radicals 2-4, particularly as they influence the C-O (k1) and C-C (k2) cleavages of intermediate oxiranylcarbinyl radical 2 and their reverse (k-1, k-2). Diversion by (MeO)3P of allyloxy radicals (3) from haloepoxides 11 and 12 fulfills a prior prediction that under conditions closer to kinetic control, products of C-O scission, not just those of C-C scission, may result. Thus, for oxiranylcarbinyl radicals from haloepoxides 11, 12, and 13, C-O scission (k1, 2 → 3) competes readily with C-C cleavage (k2, 2 → 4), even though C-C scission is favored thermodynamically.
Synthesis, characterization, and thermochemistry of (η1-C13H9)MN(CO)5 and (η5-C13H9)MN(CO)3
Decken, Andreas,MacKay, Andrew J.,Brown, Martin J.,Bottomley, Frank
, p. 2006 - 2009 (2008/10/08)
Reaction of LiC13H9 with Mn(CO)5Br at -78 °C gave (η1-C13H9)Mn(CO)5, 2. Thermal rearrangement of 2 yielded (η5-C13H9)Mn(CO)3, 1, 9, 9′
Aromatic hydrocarbon growth from indene
Lu, Mingming,Mulholland, James A.
, p. 625 - 633 (2007/10/03)
Aromatic hydrocarbon growth from indene (C9H8), which contains the five-membered ring cyclopentadienyl moiety, was investigated experimentally in a 4 s flow reactor over a temperature range 650-850°C. Major products observed were three C18H12 isomers (chrysene, benz[a]anthracene and benzo[c]phenanthrene), two C17H12 isomers (benzo[a]fluorene and benzo[b]fluorene), and two C10H8 isomers (naphthalene and benzofulvene). Reaction pathways to these products are proposed. Indenyl radical addition to indene produces a resonance-stabilized radical intermediate which further reacts by one of two routes. Rearrangement by intramolecular addition produces a bridged structure that leads to the formation of C17H12 and C10H8 products. Alternatively, β scission produces biindenyl, which leads to the formation of C18H12 products by a ring condensation mechanism analogous to that proposed for cyclopentadiene-to-naphthalene conversion. Temperature dependencies of both the partitioning between these two routes and the product isomer distributions are consistent with thermochemical modeling using semi-empirical molecular orbital methods. The results further illustrate the role of resonance-stabilized radical rearrangement in aromatic growth and condensation of systems with cyclopentadienyl moieties.
The Photochemical Generation of Isoindene and its Dimerization to Diastereomeric 1-(Indan-1-yl)indenes
Warrener, Ronald N.,Pitt, Ian G.,Russell, Richard A.
, p. 1845 - 1860 (2007/10/02)
Isoindene (1), generated by ultraviolet irradiation (Vycor filter, acetone solution) of 1,4-dihydro-1,4-methanonaphthalene-2,3-dione (14), is shown to undergo homodimerization at -60 deg C.This cycloaddition involves the intermolecular transfer of a hydrogen atom from one isoindene molecule to a second isoindene molecule in an pericyclic process.The gross structure of the resulting diastereomeric dimers was confirmed by synthesis from 1-bromoindan (25) and indenyl anion (26).The stereochemistry of the dimers was determined by comparing their dihydro derivatives (33) and (34) with authentic samples.The authentic samples were themselves prepared by cis hydrogenation (Pd/C) of (E)-2,2',3,3'-tetrahydro-1,1'-bi-1H-indenylidene (30) which yielded (34), and trans hydrogenation (Na/NH3) of (30) which formed (33) together with (34) (ratio 7:3).The (E) stereochemistry of (30), which was a critical feature in the stereochemical assignments to (33) and (34), was confirmed by n.O.e. studies on it and its (D4)derivative (32).Complete analysis of the proton, proton coupling was conducted on (32).This identified a 5J coupling between protons C3-H and C7-H which contributed a 6percent scalar coupling to the observed n.O.e. of 39percent at C7-H.This information allowed unambiguous stereochemical assignments to be made to (33).The chirality of 1,1'-bi-1H-indenyls (43) and (44), prepared by the radical coupling of 1H-inden-1-ylmagnesium bromide, was also determined by a similar hydrogenation process.
Etude de la polymerisation par voie cationique du bis(indenyl-1)d,l
Sanchez, Jean-Yves,Nicolet, Pierre,Abadie, Marc J.-M.
, p. 438 - 443 (2007/10/02)
Cationic polymerization of bis(indenyl-1)d,l was carried out in the presence of several types of initiators.The kinetic study of the polymerization of this monomer, initiated by TiCl4 at low temperature shows that the propagation rate is first order in bis(indenyl-1).Polymerization initiated by triflic acid at 50 deg C in benzene as a solvent results in low molecular weight poly bis(indenyl-1)d,l.The use of benzoyl hexafluoroantimonate leads to polymers of low polydispersity having an experimental DPn close to the theorical one.This seems to result from a fast and quantitative initiation step.
REACTIONS OF ORGANOMETHALIC COMPOUNDS CATALYZED BY THE COMPLEXES OF TRANSITION METALS. I. COUPLING OF ORGANOTIN COMPOUNDS WITH ARYL HALIDES CATALYZED BY PALLADIUM COMPLEXES
Kashin, N. A.,Bumagina, I. G.,Bumagin, N. A.,Beletskaya, I. P.
, p. 18 - 24 (2007/10/02)
The reactions of organotin compounds RSnMe3 C, C9H7 (indenyl), C13H9 (9-fluorenyl)> with aryl halides ArX , catalyzed by palladium complexes ArPdI(PPh3)2 in dichloroethane under vacuum conditions were investigated.In the reactions of RSnMe3 (where R = Ph, m-CH3C6H4, or PhCC) the RAr compounds are formed with good yields.In the stoichiometric reactions of RSnMe3 (where R = Ph or PhCC) with ArPdI(PPh3)2 (where Ar = Ph, p-NO2C6H4, or 2,4-(NO2)2C6H3> the dimers R2 are formed in addition to RAr, while in the case of the reactions of RSnMe3 (where R = C9H7 or C13H9) only R2 compounds are obtained.The possible mechanisms of the catalytic and stoichiometric reactions are discussed.
