34472-48-5

Usage

Uses

Used in Chemical Production:
1-(1-methylethylidene)-1H-indene is used as a key intermediate for the synthesis of various industrial chemicals, including dyes, plastics, and pharmaceuticals. Its presence in these applications is due to its ability to undergo further chemical reactions, contributing to the formation of a wide array of products.
Used in Pharmaceutical Industry:
In the pharmaceutical industry, 1-(1-methylethylidene)-1H-indene is used as a starting material for the synthesis of complex organic molecules with potential medicinal properties. Its unique structure allows for the creation of new drugs with specific therapeutic effects.
Used in Materials Science:
1-(1-methylethylidene)-1H-indene is utilized as a component in the development of new materials with enhanced properties. Its incorporation into polymers and other materials can improve characteristics such as strength, flexibility, and durability.
Used in Agriculture:
In agriculture, 1-(1-methylethylidene)-1H-indene may be used as a precursor for the synthesis of agrochemicals, such as pesticides and herbicides. Its role in these applications is to provide a stable and effective platform for the development of compounds that can protect crops from pests and diseases.
Used in Dye Industry:
1-(1-methylethylidene)-1H-indene is used as a building block in the production of dyes, where its chemical properties contribute to the creation of vibrant and stable colorants for various applications, including textiles, plastics, and printing inks.
Overall, the diverse applications of 1-(1-methylethylidene)-1H-indene across different industries highlight its importance as a versatile and valuable compound in modern chemistry and material science.

InChI:InChI=1/C12H12/c1-9(2)11-8-7-10-5-3-4-6-12(10)11/h3-8H,1-2H3

Upstream product

• 67-64-1 acetone 
• 95-13-6 1-indene 
• 64391-30-6 3-(1-hydroxy-1-methylethyl)indene 
• 42271-88-5 1-(2-acetoxy-2-propyl)indene 
• 819871-78-8 1-ethynyl-2-(2-methylprop-1-en-1-yl)benzene 
• 10136-84-2 Indenyl-⁽³⁾-magnesiumbromid 
• 75915-20-7 1-(2-bromo-2-propyl)indene 
• 102101-28-0 2-acetoxy-1-isopropylideneindan 
• 98800-46-5 3-(2-chloropropan-2-yl)indene 
• 64909-94-0 1-(2-chloro-2-propyl)indene 
• 42447-90-5 3-(2-acetoxypropan-2-yl)indene 
• 67-56-1 methanol 
• 20440-84-0 2-(1H-inden-1-yl)-propan-2-ol 

Downstream Products

• 65540-54-7 ethyl 3,3-dimethylspiro-2-carboxylate 
• 3661-65-2 1-isopropyl-1H-indene 
• 88-99-3 benzene-1,2-dicarboxylic acid 
• 67-64-1 acetone 
• 1149361-23-8 3-(2-benzylprop-2-yl)indene 
• 138036-89-2 3-[2-(2-phenylpropyl)]indene 
• 1332716-89-8 3-[2-(4-methylphenyl)prop-2-yl]indene 
• 1351184-37-6 1-(9-fluorenyl)-2-{1-[3-(2-(2-(1-cyclohexenyl)propyl))indenyl]}ethane 
• 1351184-38-7 ethylene-1-(9-fluorenyl)-2-{1-[3-(2-(1-cyclohexenyl)prop-2-yl)indenyl]} zirconium dichloride 
• 1610803-26-3 3-[2-(3,5-dimethylphenyl)prop-2-yl]indene 
• 1610803-28-5 1-(9-fluorenyl)-2-{1-[3-(2-benzylprop-2-yl)indenyl]}ethane 
• 1629859-52-4 1-(9-fluorenyl)-2-{3-[1-(2-benzylprop-2-yl)indenyl]}ethane 
• 1351184-33-2 3-[2-(2-cyclohexylpropyl)]indene 
• 1351184-36-5 3-{2-[2-(1-cyclohexenyl)propyl]}indene 

Relevant academic research and scientific papers

Synthetic explorations towards sterically crowded 1,2,3-substituted bis(indenyl)zirconium(IV) dichlorides

The systematic synthesis of 1,3-dialkyl-substituted 2-silylindenes and their suitability as zirconocene ligands is discussed. Unexpected reactivities rendered a number of substitution patterns unfeasible, especially for alkyl groups other than methyl in 2-(trimethylsilyl)indene derivatives, and essentially for all derivatives of 2-(dimethylsilyl)indene. The syntheses of rac/meso-bis[1-methyl-2-(trimethylsilyl)indenyljzirconium(IV) dichloride (12) and bis[1,3-dimethyl-2-(trimethylsilyl)indenyl]zirconium(IV) dichloride (13b) are de scribed. The solid-state structure of the latter displays strong deformations within the ligand framework and an unusually large C PcentroidZr-CPcentroid angle. Both, 12/MAO and 13b/MAO, displayed ethene and ethene-co-1-hexene polymerization activity. Curiously, 13b/MAO shows an extraordinary monomer selectivity, which can be rationalized by means of DFT calculations on the active site. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).

Borderline betwwen E1cB and E2 Mechanisms. Elimination of HCl from Fluorene Derivatives

The base-promoted elimination of HCl from 9-(2-chloro-2-propyl)fluorene (2-Cl) exhibits a kinetic deuterium isotope effect that varies with base strenth and solvent character, from a maximum of kH/kD = 8.1 with HO- in 25 vol percent acetonitrile in water to ca. 3 in pyridine (neat) at 25 gradC.The Broensted parameter was measured in methanol with substituted quinuclidine bases as β = 0.5.The large variation in isotope effect could be the result of a varying degree of internal return from a tightly hydrogen-bonded carbanion.However, analysis of β as a function of substrate acidity, leaving group,,and α-substituents suggest that the elimination of HCl from the fluorene derivatives is of E2 type.For example, a change in leaving group from AcO- to Cl- corresponds to a decrease in β from 0.73 to 0.56 for the 9-(X-methyl)fluorene (3-X) series.It is concluded that the reaction coordinate has a relatively large horizontal component corresponding to proton transfer.

Borderline between ElcB and E2 mechanisms. Chlorine isotope effects in base-promoted elimination reactions

The chlorine leaving group isotope effect has been measured for the base-promoted elimination reaction of 1-(2-chloro-2-propyl)indene (1-Cl) in methanol at 30 °C: k35/k37 = 1.0086 ± 0.0007 with methoxide as the base and k35/k37 = 1.0101 ± 0.0001 with triethylamine (TEA) as the base. These very large chlorine isotope effects combined with large kinetic deuterium isotope effects of 7.1 and 8.4, respectively, are consistent not with the irreversible ElcB mechanism proposed previously (J. Am. Chem. Soc. 1977, 99, 7926) but with the E2 mechanism with transition states having large amounts of hydron transfer and very extensive cleavage of the bond to chlorine.

Enlarged Deuterium Isotope Effects in Oxyanion-Catalyzad 1,3 Proton Transfer Competing with 1,2 Elimination as a Probe of a Common Tightly Hydrogen-Bonded Intermediate

The reaction of 1-(2-acetoxy-2-propyl)indene (1-h) or 1-(2-acetoxy-2-propyl)indene (1-d) with p-NO2PhO- in methanol buffered with p-NO2PhOH results in base-catalyzed 1,3 proton transfer, yielding 3-(2-acetoxy-2-propyl)indene (2-h) and 3-(2-acetoxy-2-propyl)indene (2-d), respectively, in competition with base-promoted 1,2-elimination producing 1-isopropylideneindene (3-h) and 1-isopropylideneindene (3-d), respectively.The overall deuterium isotope effect on the reaction of 1 was measured as (k12H + k13H)/(k12D + k13D) = 5.2, which is composed of the rearrangement isotope effect k12H/k12D = 12.2 +/- 1.0 and the elimination isotope effect k13H/k13D = 3.6.The enlarged rearrangement isotope effect shows that the intramolecularity of the 1,3 proton-transfer reaction is substantial.The intramolecularity was determined as ca. 87percent for = 0.24 M and ca. 80percent for = 0.71 M by analyzing the 2H content of the product 2-d.The amplified isotope effect on the 1,3-prototropic shift together with the attenuated elimination isotope effect shows that the two reactions are coupled via at least one common intermediate, which is concluded to be a tightly hydrogen-bonded complex between the protonated base and the carbanion.An increase in basicity of the oxyanion favors elimination at the expense of rearrangement.Reaction of 2-h and 2-d predominantly give 1,4 elimination accompanied by a trace of competing 1,3 proton transfer.The isotope effect k23H/k23D was measured to 2.5; it is small owing to a large amount of internal return.

Experimental and DFT study on titanium-based half-sandwich metallocene catalysts and their application for production of 1-hexene from ethylene

Different types of [Ind-C(R)-Phenyl]TiCl3 catalysts based on pendant arene containing indenyl (Ind) ligand bearing various types of bridges (R=cyclo‐C5H10 (C1), (CH3)2 (C2), 4-tBu-cyclo‐C5H9 (C3), and cyclo‐C6H12 (C4)) have been synthesized, and used in the ethylene trimerization to 1-hexene in the presence of methyl aluminoxane (MAO) as co-catalyst. The reaction conditions were first optimized in C2 catalyst case, where the highest 1-hexene product was achieved at the catalyst concentration, temperature and ethylene pressure of 1.5× 10?3 M, 40 °C, and 8 bar, respectively. During this optimization and under specific reaction conditions, a switching behavior from ethylene trimerization to polymerization was also detected, as an undesired reaction. At the optimized conditions, synthesized catalysts showed the following trend toward both 1-hexene yield and selectivity: C1>C2>C3>C4. Then, to shed light on the possible reaction mechanisms and to confirm the activity trend obtained in experimental section, density functional theory (DFT) calculations were employed. In this line, obtained results for activity trend in the simulation studies fit well with the experiments. According to both experimental and DFT results, the highest catalytic activity was observed in the presence of the catalyst with a cyclohexane middle bridge (C1).

Optimization of ethylene trimerization using catalysts based on TiCl3/half-sandwich ligands

Catalytic trimerization of ethylene using three titanium-based complexes [η5-C9H6C(R)thienyl]TiCl3 with various types of bridges (R?=?cyclo-C5H10 (C1), cyclo-C4H8 (C2) and (CH3)2 (C3)) has been successfully optimized and compared. First of all, three benzofulvene precursors, C9H6C(R), were synthesized. Then the corresponding indenyl-based ligands were obtained via the reaction of the precursors with thienyllithium. The final titanium-based catalysts display a distorted tetrahedral geometry, as expected for Ti(IV), with the ligand coordinated with a hemilabile behaviour. The structures of the compounds were confirmed on the basis of various analyses. The effect of catalyst concentration, ethylene pressure, reaction temperature and nature of the bridge as the significant factor affecting coordination and orientation of thienyl group relative to the metal centre on 1-hexene (1-C6) productivity and selectivity was investigated. Results revealed that the bulky bridge groups such as cyclo-C5H10 and cyclo-C4H8 are appropriate for ethylene trimerization due to the closer coordination of sulfur atom with Ti, especially in cationic state, and catalyst C2 with cyclo-C4H8 bridge exhibits moderate productivity equal to 785?kg 1-C6?(mol Ti)?1?h?1. According to the results, ethylene at a pressure of 10?bar, 50°C and 1.5?μmol of catalyst were selected as the best conditions for obtaining 1-C6 with high productivity and selectivity. The presence of indenyl enhances the thermal stability of the catalysts and preserves their activity in higher temperatures such as 50 and 80°C.

Attempts to prepare an all-carbon indigoid system

First attempts are described to prepare a precursor for an all-carbon analog of indigo, the tetracyclic triene 4. Starting from indan-2-one (9) the α-methylene ketone 13 was prepared. Upon subjecting this compound to a McMurry coupling reaction, it dimerized to the bis-indene derivative 17, rather than providing the tetramethyl derivative of 4, the hydrocarbon 14. In a second approach, indan-1-one (18) was dimerized to the conjugated enedione 21 through the bis-1-indene dimer 19. All attempts to methylenate 21 failed, however. When 19 was treated with the Tebbe reagent, the dimer 23 was produced, presumably through a Cope reaction of the intermediately generated isomer 22. The bis-indene derivative 23 can be alkylated with 1,2-dibromoethane to produce a 1:1 mixture of the spiro compounds 24 and 25. Although 9 could be reductively dimerized to 30, the conversion of this olefin to 14 failed.

Rutheniun-catalyzed cycloisomerization of o-(ethynyl)phenylalkenes to diene derivatives via skeletal rearrangement

Treatment of a series of 2′,2′-disubstituted (oethynyl)styrenes with TpRu(PPh3)(CH3CN)2PF6 (10 mol %) in benzene (80°C, 12-18 h) efficiently gave 2-alkenyl-1H-indene derivatives. This catalytic reaction represents an atypical enyne cycloisomerization with skeletal rearrangement of starting enyne, where the C=C bond is completely cleaved and inserted by the terminal alkynyl carbon. The reaction mechanism was elucidated by a series of deuterium and 13C labeling experiments, as well as by changing the substituents at the phenyl moieties. The mechanism is proposed to involve the following key steps: 5-endo-dig cyclization of ruthenium-vinylidene intermediate, a nonclassical ion formation, and the "methylenecyclopropane-trimethylenemethane" rearrangement.

SYNTHESIS OF ETHYL 3,3-DIALKYL-3'-ALKYLSPIRO-2-CARBOXYLATES

The alkylation of indene with ultrasonic activation gave quantitative yields of 3-alkylindenes.When heated with ketones in the presence of bases, the latter gave benzofulvenes capable of entering into reaction with ethyl(dimethylsulfuranylidene)acetate with the formation of spirocyclopropane structures.A series of benzofulvenes and the corresponding ethyl 3,3-dialkyl-3'-alkylspiro-2-carboxylates were obtained.

Reactions of an Allylic Carbocation with Nucleophiles in Aqueous Solvents

The allylic carbocation formed from 3-(2-X-propan-2-yl)indene (1-X) (X = Cl, OAc, or OH2+), or from 2-acetoxy-1-isopropylideneindan (2-OAc) in aqueous solvents containing ca. 75 vol percent water reacts rapidly with nucleophiles.The selectivity is very low: βnuc ca. 0.07 with alcohols as nucleophiles and βnuc ca. 0.03 with substituted acetate anions.The nucleophile attacks at both ends of the allylic system but preferentially at the exocyclic carbon atom, giving the thermodynamically more stable product.Azide anion reacts with the carbocation about 50 times as fast as does water.The solvolysis of the allylic isomers (1-OAc) and (2-OAc) is accompanied by intramolecular rearrangement of the acetates as well as hydron abstraction by the leaving acetate anion, yielding the 1,2- and 1,4-elimination products.The elimination product compositions are quite different, which indicates two discrete ion-pair intermediates.It is concluded also that the isomerization proceeds by an ion-pair route, since in less polar solvents it has only been observed along with solvolysis and elimination.The experimental results for the acetates accomodate well a mechanism in which solvolysis, rearrangement, and elimination are connected via two contact ion-pair intermediates.