85864-86-4Relevant academic research and scientific papers
Synthesis and properties of 9-alkyl- and 9-arylcyclopenta[a]phenalenes
Shea, Kevin M.,Lee, Katherine L.,Danheiser, Rick L.
, p. 2353 - 2356 (2000)
(equation presented) Two strategies for the synthesis of cyclopenta[a]phenalenes are described. NMR, X-ray diffraction, and cyclic voltammetry studies of simple alkyl- and aryl-substituted derivatives are reported for the first time.
Mechanistic studies of hoveyda-grubbs metathesis catalysts bearing S-, Br-, I-, and N-coordinating naphthalene ligands
Grudzien, Krzysztof,Zukowska, Karolina,Malinska, Maura,Wozniak, Krzysztof,Barbasiewicz, Michal
, p. 2819 - 2828 (2014/03/21)
Derivatives of the Hoveyda-Grubbs complex bearing S-, Br-, I-, and N-coordinating naphthalene ligands were synthesized and characterized with NMR and X-ray studies. Depending on the arrangement of the coordinating sites on the naphthalene core, the isomeric catalysts differ in activity in model metathesis reactions. In particular, complexes with the Rui￡CH bond adjacent to the second aromatic ring of the ligand suffer from difficulties experienced on their preparation and initiation. The behavior most probably derives from steric hindrance around the double bond and repulsive intraligand interactions, which result in abnormal chemical shifts of benzylidene protons observed with 1HNMR. Furthermore EXSY studies revealed that the halogen-chelated ruthenium complexes display an equilibrium, in which major cis-Cl2 structures are accompanied with small amounts of isomeric forms. In general, contents of the minor forms, measured at 80°C, correlate with the observed activity trends of the catalysts, although some exceptions complicate the mechanistic picture. We assume that for the family of halogen-chelated metathesis catalysts the initiation mechanism starts with the cis-Cl 2a?trans-Cl2 isomerization, although further steps may become rate-limiting for selected systems. Isomerization first: A family of halogen-chelated Hoveyda-Grubbs complexes displays a cis-Cl2a?trans-Cl2 equilibrium in solution. Relative contents of the minor trans forms go along with the activity of the metathesis catalysts, suggesting its participation in the initiation mechanism (see figure). A unique effect of the naphthalene ligands enables control of the activity over a broad range, from moderately achieve to dormant, and was manifested in 1HNMR for complexes with repulsive H×××H intraligand interactions (Mes=Mesityl).
Studies in Acyl C-H activation via aryl and alkyl to acyl "through space" migration of palladium
Kesharwani, Tanay,Verma, Akhilesh K.,Emrich, Daniel,Ward, Jeffrey A.,Larock, Richard C.
supporting information; experimental part, p. 2591 - 2593 (2009/10/23)
Examples of the 1,4-migration of a palladium moiety in aryl- and alkylpalladium intermediates to the acyl position of an aldehyde or formamide have been observed. The resulting acylpalladium intermediate can undergo ester or carbamate formation by reaction with an alcohol; decarbonylation, followed by β hydride elimination to an alkene; reaction with an organomercurial to form an ester; or alkene insertion. Deuterium-labeling studies have been used to confirm the palladium migration mechanism.
Chemistry of 8-Substituted 1-Naphtylmethylenes and 2-Substituted Benzylidenes. A simple Entry to 1H-Cyclobutanaphthalenes
Bailey, R. J.,Card, P. J.,Shechter, H.
, p. 6096 - 6103 (2007/10/02)
Study has been made of neighobing heteroatom interaction in thermolysis and photolysis of proximally substituted aryldiazomethanes.Thus, (8-bromo-1-naphthyl)diazomethane (1c) isomerize at 132 deg C to 9-bromo- (18a), 9-iodo- (18b), and 6,9-dichloro-3H-benzindazoles (18c).Indazoles 18a and 18b are reduced by lithium aluminum hydride to 3H-benzindazole (21), identical with that from decomposition of N-(1-methyl-2-naphthyl)-N-nitrosoacetamide (19). 1-Naphthyldiazomethane (1e) does not isomerize however to 21; in benzene at -78 deg c, 1e converts to trans-bis(1-naphthyl)ethylene (22b), 1-naphthalzine (26), and 7-(1-naphthyl)cycloheptatriene (24) wich rearranges to 1-(1-naphthyl)cycloheptatriene (25) whean heated.Irradiation of 1a in ethyl ether results in trans-bis(8-bromo-1-naphthyl)ethylene (22c) and 1-bromo-1Hcyclobutanaphthalene (4a), the first aryne bridged in its peri positions by a single carbon atom moiety.Aqueous silver nitrate converts 4a tp 1H-cyclobutanaphthyl nitrate (4b) and 1-naphthaldehyde (28), presumably by ring opening of 1-hydroxy-1H-cyclobutanaphhtalene (27).Reaction of 4a with magnesium and hydrolysis of the resulting Grignard reagent yield 1H-cyclobutanaphthalene (4d), a hydrocarbon acid wich udergoes deuterium exchange at C-1 considerably slower than to acenaphthene (29) and diphenylmethane (30).Thermolysis and photolysis of diazomethane (1d) to give 2-methyl-2H-naphthothiophene (33) are of note in that methylthio participation in 8-(methylthio)-1-naphthylidene (2d) and thia-Stevens rearrangement appear to be involved. (o-Iodophenyl)diazomethane (5a) thermolyzes to trans-bis(o-iodophenyl)ethylene and o-iodobenzalazine (36); products of reaction of the iodine moiety with the carbenic center in o-iodobenzylidene (6a) were not found.Thermolysis however of (o-(methylthio)phenyl)diazpmethane (5b) results in inrtamolecular C-H insertion to yield 4,5-dihydrothiophene (37) along with trans-bisethylene (38) and o-(methylthio)benzalazine(39).Intermolecular carbenic interception does occur in photolysis of 5b iin that 2-(2-ethoxy-1-propyl)thioanisole (40) is formed along with 398 and 39.The mechanisms of the various participation processes in the above substituted 1-naphthylidenes are discussed.
