2177-47-1Relevant articles and documents
Cycloaddition Reactions of Indenes. 2. Reactions with Dimethyl Acetylenedicarboxylate and Maleic Anhydride
Noland, Wayland E.,Kameswaran, Venkataraman,Landucci, Lawrence L.
, p. 4564 - 4572 (1980)
1H-Indenes (1) react with dimethyl acetylenedicarboxylate (DMAD), unlike maleic anhydride and other ethylenic dienophiles, without prior isomerization to 2H-indenes (2), giving a 1:1 Diels-Alder adduct (6) formed with destruction of the aromaticity of the benzene ring. This intermediate, not isolated in the present work, appears to serve as the precursor for all further adducts. Thus, 1H-indene (1a) and 1-methyl-1H-indene (1b), but not the more sterically hindered 1-ethyl-1H-indene, react with DMAD in refluxing benzene (with 1a) or toluene (with 1b) via a 1,2-cycloaddition to 6 to give solid 1:2 adducts (7a, 34percent; 7b, 30percent). In refluxing xylene the reaction goes further to give a 1:3 adduct (11a; 40percent from 1a, 71percent from 7a) formed by a Diels-Alder addition of a third molecule of DMAD across the remaining diene system of 7a. Reaction of 2-methyl-1H-indene (1c) with DMAD in refluxing xylene gave the corresponding 1:3 adduct (11c, 5-6percent), but an attempt in refluxing toluene to isolate a solid 1:2 adduct (7c) was unsuccessful.A 3-substituent in the 1H-indene, which becomes a 4-substituent in 6, blocks the 1,2-cycloaddition (to give 7) and diverts the DMAD to the cyclohexadiene system of 6, where a Diels-Alder reaction occurs in refluxing xylene to give another type of 1:2 adduct (8). The following 3-substituted 1H-indenes (1) gave 1:2 adducts of type 8: 3-methyl- (8d, 41percent), 3-ethyl- (8e, 40percent), 1,3-dimethyl- (8f, 31percent), 2,3-dimethyl- (8g, 19percent), 3-carboxy- (8l, 74percent), 3-(methoxycarbonyl)-(8m, 66percent), and 3-cyano-1H-indene (8n, 63percent). Alkaline hydrolysis of 8l and acidification to pH 2 gave the monosodium salt (91percent) of the corresponding pentacarboxylic acid (13l). Hydrogenation of 8l over PtO2 gave a tetrahydro derivative (14l, 100percent). That maleic anhydride can take the place of the second (but not the first) molecule of DMAD in 8 is shown by the formation of a 1:1:1 mixed adduct (10l, 17percent) along with the 1:2 adduct (8l, 18percent) from reaction of 1l, DMAD, and maleic anhydride in a 1:2:2 molar ratio in refluxing xylene. A similar 1:1:1 mixed adduct (10n, 59percent), but no 1:2 adduct (8n), was isolated from the corresponding reaction of 1n, DMAD, and maleic anhydride in a 1:1:1 molar ratio. Similarly, maleic anhydride can take the place of the third molecule of DMAD in the 1:3 adduct 11. Thus, reaction of 7a and 7b with maleic anhydride in refluxing xylene gave the corresponding 1:2:1 mixed adducts (12a, 69percent; 12b, 32percent), formed by Diels-Alder addition across the cyclohexadiene system of 7a and 7b. Reaction of 1-methyl-1H-indene (1b), DMAD, and maleic anhydride in a 1:2:1 molar ratio in refluxing xylene also gave 12b (31percent) but no 1:3 adduct (11b). Methyl esterification of 12a gave the corresponding hexamethyl ester (15a, 52percent). On the basis of the shielding effects of neighboring ethylene groups on the methylene bridge protons, an NMR rationale has been developed for assignment of stereochemistry to the adducts 8-12.
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Juge,F.E.,Fry,A.
, p. 1876 - 1881 (1970)
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Palladium-Catalyzed Cyclization of Benzyl Halides and Related Electrophiles Containing Alkenes and Alkynes as a Novel Route to Carbocycles
Wu, Guang-zhong,Lamaty, Frederic,Negishi, Ei-ichi
, p. 2507 - 2508 (1989)
Treatment of benzyl halides and related electrophiles containing alkene and alkyne groups with a catalytic amount of Pd complexes, such as Pd(PPh3)4, provides the corresponding cyclization products containing five- through seven-membered rings often with retention of the alkene regiochemistry.
Alkyl-substituted indenyl titanium precursors for syndiospecific ziegler-natta polymerization of styrene
Ready, Thomas E.,Chien, James C.W.,Rausch, Marvin D.
, p. 21 - 28 (1996)
A variety of 1- and 3-substituted alkylindenes (R = H, Me, Et, tert-butyl, Me3Si) as well as 2-methylindene and 3-(methylthio)indene have been prepared in good yields. The substituted indenes were converted into trimethylsilyl derivatives via reactions of intermediate organolithium complexes with chlorotrimethylsilane. The corresponding titanium complexes, (R-Ind)TiCl3, were synthesized in excellent yield from reactions of the trimethylsilyl derivatives with TiCl4. The titanium complexes were evaluated as styrene polymerization catalysts in toluene solution when activated by methylaluminoxane. Activities increased in the order: Cp 4 Ind 3Si, corresponding to an increase in the steric bulk of the substituent in the catalyst precursor. 1-(MeS)IndTiCl3 was found to be ineffective as a styrene polymerization catalyst. Syndiospecificities of the titanium complexes were generally very good (65-98%).
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Alexander,Mudrak
, p. 59 (1951)
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CO extrusion in homogeneous gold catalysis: Reactivity of gold acyl species generated through water addition to gold vinylidenes
Bucher, Janina,St?sser, Tim,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
supporting information, p. 1666 - 1670 (2015/01/30)
Herein, we describe a new gold-catalyzed decarbonylative indene synthesis. Synergistic σ,π-activation of diyne substrates leads to gold vinylidene intermediates, which upon addition of water are transformed into gold acyl species, a type of organogold compound hitherto only scarcely reported. The latter are shown to undergo extrusion of CO, an elementary step completely unknown for homogeneous gold catalysis. By tuning the electronic and steric properties of the starting diyne systems, this new reactivity could be exploited for the synthesis of indene derivatives in high yields.
Acid catalysed reaction of indanones, tetralones and benzosuberone with neopentyl glycol and other alkanediols under forced conditions
Imai, Masao,Morais, Goreti Ribeiro,Al-Hindawi, Bassam,Al-Sulaibi, Mazen A.M.,Meetani, Mohammad,Thiemann, Thies
experimental part, p. 325 - 329 (2010/10/19)
Upon reaction with an excess of 2,2-dimethylpropane-1,3-diol (neopentyl glycol, NPG) under acid catalysis, indanones and tetralones yield indenes and dihydronaphthalenes, respectively. The reaction can also be carried out with butane-1,3-diol.
