40702-26-9

Usage

Synthesis Reference(s)

Tetrahedron Letters, 30, p. 1357, 1989 DOI: 10.1016/S0040-4039(00)99464-4

InChI:InChI=1/C10H16O/c1-8-4-5-10(3,7-11)6-9(8)2/h7H,4-6H2,1-3H3

Upstream product

• 78-85-3 2-methylpropenal 
• 513-81-5 2,3-dimethyl-buta-1,3-diene 
• 2094-75-9 2,2-dimethylbutyraldehyde 
• 106-99-0 buta-1,3-diene 

Downstream Products

• 85288-62-6 1-(1,3,4-trimethyl-cyclohex-3-en-1-yl)ethanol 
• 69461-64-9 1-(1,3,4-trimethylcyclohex-3-en-1-yl)ethanone 

Relevant academic research and scientific papers

Developing potentially useful organometallic Lewis acid catalysts: (η-cyclopentadienyl)zirconium trichloride derivatives

The organometallic Lewis acid (η-cyclopentadienyl)zirconium trichloride (2) was obtained from bis(cyclopentadienyl)zirconium dichloride (1) and chlorine by means of a radical induced metal-Cp bond cleavage.Reaction of 2 with tetrahydrofuran gave the CpZrC

Sequential Diels-Alder reaction/rearrangement sequence: Synthesis of functionalized bicyclo[2.2.1]heptane derivatives and revision of their relative configuration

A sequential Diels-Alder reaction/rearrangement sequence was developed for the synthesis of diverse functionalized bicyclo[2.2.1]heptanes as novel floral and woody odorants. The outcome of the rearrangement depended on the substitution pattern of the dien

Bis-selenonium Cations as Bidentate Chalcogen Bond Donors in Catalysis

Lewis acids are frequently employed in catalysis but they often suffer from high moisture sensitivity. In many reactions, catalysts are deactivated because of the problem that strong Lewis acids also bond to the products. In this research, hydrolytically stable bidentate Lewis acid catalysts derived from selenonium dicationic centers have been developed. The bis-selenonium catalysts are employed in the activation of imine and carbonyl groups in various transformations with good yields and selectivity. Lewis acidity of the bis-selenonium salts was found to be stronger than that of the monoselenonium systems, attributed to the synergistic effect of the two cationic selenonium centers. In addition, the bis-selenonium catalysts are not inhibited by strong bases or moisture.

STRONGLY LEWIS ACIDIC METAL-ORGANIC FRAMEWORKS FOR CONTINUOUS FLOW CATALYSIS

Lewis acidic metal-organic framework (MOF) materials comprising triflate-coordinated metal nodes are described. The materials can be used as heterogenous catalysts in a wide range of organic group transformations, including Diels-Alder reactions, epoxide-ring opening reactions, Friedel-Crafts acylation reactions and alkene hydroalkoxylation reactions. The MOFs can also be prepared with metallated organic bridging ligands to provide heterogenous catalysts for tandem reactions and/or prepared as composites with support particles for use in columns of continuous flow reactor systems. Methods of preparing and using the MOF materials and their composites are also described.

Strongly Lewis Acidic Metal-Organic Frameworks for Continuous Flow Catalysis

The synthesis of highly acidic metal-organic frameworks (MOFs) has attracted significant research interest in recent years. We report here the design of a strongly Lewis acidic MOF, ZrOTf-BTC, through two-step transformation of MOF-808 (Zr-BTC) secondary building units (SBUs). Zr-BTC was first treated with 1 M hydrochloric acid solution to afford ZrOH-BTC by replacing each bridging formate group with a pair of hydroxide and water groups. The resultant ZrOH-BTC was further treated with trimethylsilyl triflate (Me3SiOTf) to afford ZrOTf-BTC by taking advantage of the oxophilicity of the Me3Si group. Electron paramagnetic resonance spectra of Zr-bound superoxide and fluorescence spectra of Zr-bound N-methylacridone provided a quantitative measurement of Lewis acidity of ZrOTf-BTC with an energy splitting (?E) of 0.99 eV between the ?x? and ?y? orbitals, which is competitive to the homogeneous benchmark Sc(OTf)3. ZrOTf-BTC was shown to be a highly active solid Lewis acid catalyst for a broad range of important organic transformations under mild conditions, including Diels-Alder reaction, epoxide ring-opening reaction, Friedel-Crafts acylation, and alkene hydroalkoxylation reaction. The MOF catalyst outperformed Sc(OTf)3 in terms of both catalytic activity and catalyst lifetime. Moreover, we developed a ZrOTf-BTC?SiO2 composite as an efficient solid Lewis acid catalyst for continuous flow catalysis. The Zr centers in ZrOTf-BTC?SiO2 feature identical coordination environment to ZrOTf-BTC based on spectroscopic evidence. ZrOTf-BTC?SiO2 displayed exceptionally high turnover numbers (TONs) of 1700 for Diels-Alder reaction, 2700 for epoxide ring-opening reaction, and 326 for Friedel-Crafts acylation under flow conditions. We have thus created strongly Lewis acidic sites in MOFs via triflation and constructed the MOF?SiO2 composite for continuous flow catalysis of important organic transformations.

Diazepane Carboxylates as Organocatalysts in the Diels–Alder Reaction of α-Substituted Enals

Ethyl diazepane carboxylate efficiently catalyzes the Diels–Alder cycloaddition of α-substituted-α,β-unsaturated aldehydes via iminium ion organocatalysis. The reaction is applicable to a range of dienes and dienophiles and generally proceeds at room temperature in the presence of 5 mol-% catalyst and 2.5 mol-% triflic acid co-catalyst. The incorporation of a stereogenic center on the diazepane backbone in combination with a menthyl carbamate produces a catalyst which affords enantioselectivities of 70–95 % ee for the cycloaddition of cyclopentadiene with a range of dienophiles. The enantioselectivity is rationalized via a transition state in which electrostatic stabilization by the carboxylate directs the diene to the more hindered face of the dienophile.

Synthesis of a Chiral Borate Counteranion, Its Trityl Salt, and Application Thereof in Lewis-Acid Catalysis

The preparation of a chiral derivative of [B(C6F5)4]– in which the fluorine atom in the para position of each of the C6F5 groups is replaced by a 1,1′-binaphthalen-2-yl group is described. The new counteranion was isolated as its lithium, sodium, and trityl salts. The chiral trityl salt was then used as a catalyst in selected counteranion-directed Diels–Alder reactions and a Mukaiyama aldol addition, but no asymmetric induction was achieved. Application of the chiral trityl salt to the generation of silicon cations by silicon-to-carbon hydride transfer from hydrosilanes failed, presumably as a result of the incompatibility of the relatively electron-rich naphthyl groups in the borate and the cationic silicon electrophiles.

Carbocations as lewis acid catalysts in diels-alder and Michael addition reactions

In general, Lewis acid catalysts are metal-based compounds that owe their reactivity to a low-lying empty orbital. However, one potential Lewis acid that has received negligible attention as a catalyst is the carbocation. We have demonstrated the potential of the carbocation as a highly powerful Lewis acid catalyst for organic reactions. The stable and easily available triphenylmethyl (trityl) cation was found to be a highly efficient catalyst for the Diels-Alder reaction for a range of substrates. Catalyst loadings as low as 500 ppm, excellent yields, and good endo/exo selectivities were achieved. Furthermore, by changing the electronic properties of the substituents on the tritylium ion, the Lewis acidity of the catalyst could be tuned to control the outcome of the reaction. The ability of this carbocation as a Lewis acid catalyst was also further extended to the Michael reaction. Copyright

Application of electron-withdrawing coordinatively unsaturated η6-arene β-diketiminato-Ruthenium complexes in Lewis acid catalyzed Diels-Alder reactions

Utilizing the aza-Wittig reaction involving the ylid 3,5-(CF 3)2C6H3NPPh3 and 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, a highly fluorinated and electron-withdrawing β-diketiminate was obtained. Using strong bases, nBuLi, Ag2O, or TlOEt, the corresponding β-diketiminato-Li, -Ag, or -Tl chelated complexes were prepared. Subsequent in situ transmetalation with (Ru(η6-C6H6)Cl2) 2 or (Ru(η6-p-cymene)Cl2)2 afforded the half-sandwich chloro-substituted Ru(II) β-diketimino complexes in high yield. The synthesis of the Lewis acidic catalysts featuring a vacant coordination site at the metal center was accomplished using [Na]BArF (BArF = tetrakis[3,5-bis(trifluoromethyl)phenyl]boron). These complexes are active for the Lewis acid catalyzed Diels-Alder reaction between α,β-unsaturated aldehydes, that is, methacrolein, acrolein, and dienes, that is, cyclopentadiene and 2,3-dimethyl-1,3-butadiene, with conversions in the range of 66-98% under mild conditions. Whereas the herein described catalysts generally promote exo selectivity of the [4 + 2] cycloaddition between methacrolein and cyclopentadiene, the reaction involving acrolein shows predominantly the formation of the endo adduct, similar to that observed for the noncatalyzed reaction. Importantly, the coordinatively unsaturated complexes demonstrate moderate Lewis acidity, which allows for the controlled reaction between methacrolein and 2,3-dimethyl-1,3-butadiene to 1,3,4-trimethyl-3-cyclohexene-1- carboxaldehyde without further isomerization to the bicyclic ketone, which is in contrast to strong Lewis acidic catalysts based on transition metals or main-group elements reported in the literature.

Synthesis, characterization, and catalytic properties of new electrophilic iridium(III) complexes containing the (R)-(+)-2,2,′-binaphthyl Ligand

The oxidative addition of MeI to the Ir(I) square-planar complex IrI(CO)((R)-(+)-BINAP) where (R)-(+)-BINAP = (R)-(+)-2,2′- bis(diphenylphosphino)-1,′-binaphthyl)) results in the formation of two diastereomers in a 2:1 ratio of the Ir(III) oxidative addit