38259-00-6

Upstream product

• 1165952-91-9 cyclohexa-1,3-diene 
• 107-02-8 acrolein 

Downstream Products

• 5019-91-0 (bicyclo[2.2.2]octan-2-yl)methanol 
• 4517-47-9 endo-5-methylbicyclo<2.2.2>oct-2-ene 
• 4517-47-9 5-exo-methylbicyclo<2.2.2>oct-2-ene 
• 931-64-6 norbornene 
• 19026-97-2 twistbrendane 
• 111036-01-2 2-(pyrrolidinomethylene)-bicyclo<2.2.2>octane 
• 19386-05-1 5-Methylenbicyclo<2.2.2>oct-2-en 

Relevant academic research and scientific papers

Immobilization of a soluble metal complex in an organic network. Remarkable catalytic performance of a porous dialkoxyzirconium polyphenoxide as a functional organic zeolite analogue

Treatment of anthracenebisresorcinol 1 (a tetraphenol) with Zr(O(t)Bu)4 in THF results in polycondensation to give an O-Zr-O network and affords a poly(dialkoxyzirconium phenoxide), 14- · 2[Zr(O(t)Bu)2] (Zr host), in quantitative yield as an insoluble, amorphous, microporous powder with a particle size of ~0.7 μm, a pore size of ~0.7 nm, and a specific surface area of ~200 m2/g. The powder exhibits reversible Langmuir-type adsorption/desorption of N2 at 77 K and hexane at 298 K. Adsorption and coadsorption of ethyl acetate, benzene, and other polar and apolar guests also occurs readily at 298 K. The Zr host catalyzes the Diels-Alder reaction of acrolein with 1,3-cyclohexadiene in a remarkable manner. As a solid metal- organic catalyst, it has a formula-based turnover rate constant of 40 h-1, which far exceeds those of its components, i.e., the soluble Lewis acid Zr(O(t)Bu)4 (0.1 h-1) and the hydrogen-bonded insoluble organic network 1 (0.3 h-1). The solid catalyst can be easily separated from the organic product, which is not contaminated with Zr or the reactants. The recovered catalyst can be used repeatedly without deactivation. The reaction can also be conducted in a flow system with the insoluble Zr host catalyst and a reactant mixture as a mobile phase. The remarkable catalytic performance of the Zr host and its easy preparation suggest that insoluble microporous metal-organic solid catalysts are workup-free and waste-free as well as resource- and energy-saving.

Iodine-Catalyzed Diels-Alder Reactions

The Diels-Alder cycloaddition is the most popular pericyclic reaction with numerous applications in synthesis and catalysis. We now demonstrate that we can perform this reaction under mild and metal-free conditions relying on molecular iodine as the catalyst. Cycloadditions with cyclohexadiene, cyclopentadiene, or isoprene with various dienophiles can be performed typically within minutes in moderate to good yields and high endo selectivity. The mechanistic studies including kinetic and DFT investigations clearly indicate a halogen-bond activation and rule out other modes of activation. Furthermore, iodine performs equally well as typical metallic Lewis acids like AlCl3, SnCl4, or TiCl4.

Carbon's Three-Center, Four-Electron Tetrel Bond, Treated Experimentally

Tetrel bonding is the noncovalent interaction of group IV elements with electron donors. It is a weak, directional interaction that resembles hydrogen and halogen bonding yet remains barely explored. Herein, we present an experimental investigation of the

Synthetic studies toward polytwistane hydrocarbon nanorods

A synthetic strategy toward the intriguing hydrocarbon nanorod polytwistane is outlined. Our approach aims toward the polymerization of acetylene starting from precursors that would provide a helical bias for the formation of polytwistane. Both transition-metal-catalyzed and radical polymerizations were investigated. Two potential initiator molecules were synthesized that could be used for either approach. Although the intended regioselectivities were not observed, unusual organopalladium complexes and numerous compounds with novel carbon skeletons were obtained.

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

Bromination and accompanying rearrangement of the polycyclic oxetane 2,4-oxytwistane

Bromination of the polycyclic oxetane 2,4-oxytwistane (rac-(1R,3S,4R,7S,9R,11S)-2-oxatetracyclo-[5.3.1.03,11.04,9]undecane) was undertaken in order to form 2,4-dibromotwistane. The oxetane was subjected to the mild reagent combinatio

Silylium ion-catalyzed challenging Diels-Alder reactions: The danger of hidden proton catalysis with strong Lewis acids

The pronounced Lewis acidity of tricoordinate silicon cations brings about unusual reactivity in Lewis acid catalysis. The downside of catalysis with strong Lewis acids is, though, that these do have the potential to mediate the formation of protons by various mechanisms, and the thus released Bronsted acid might even outcompete the Lewis acid as the true catalyst. That is an often ignored point. One way of eliminating a hidden proton-catalyzed pathway is to add a proton scavenger. The low-temperature Diels-Alder reactions catalyzed by our ferrocene-stabilized silicon cation are such a case where the possibility of proton catalysis must be meticulously examined. Addition of the common hindered base 2,6-di-tert-butylpyridine resulted, however, in slow decomposition along with formation of the corresponding pyridinium ion. Quantitative deprotonation of the silicon cation was observed with more basic (Mes)3P to yield the phosphonium ion. A deuterium-labeling experiment verified that the proton is abstracted from the ferrocene backbone. A reasonable mechanism of the proton formation is proposed on the basis of quantum-chemical calculations. This is, admittedly, a particular case but suggests that the use of proton scavengers must be carefully scrutinized, as proton formation might be provoked rather than prevented. Proton-catalyzed Diels-Alder reactions are not well-documented in the literature, and a representative survey employing TfOH is included here. The outcome of these catalyses is compared with our silylium ion-catalyzed Diels-Alder reactions, thereby clearly corroborating that hidden Bronsted acid catalysis is not operating with our Lewis acid. Several simple-looking but challenging Diels-Alder reactions with exceptionally rare dienophile/enophile combinations are reported. Another indication is obtained from the chemoselectivity of the catalyses. The silylium ion-catalyzed Diels-Alder reaction is general with regard to the oxidation level of the α,β-unsaturated dienophile (carbonyl and carboxyl), whereas proton catalysis is limited to carbonyl compounds.

Erbium triflate in ionic liquids: A recyclable system of improving selectivity in Diels-Alder reactions

The efficiency of Er(OTf)3 in promoting the Diels-Alder reactions between different dienes and dienophiles in ionic liquids has been investigated. Compared with the analogous cycloadditions performed in conventional solvents shorter reaction times are required to obtain good/excellent yields. In most cases an enhancement of regio- and endo:exo selectivity was observed. The role of the ionic liquid, as a function of the cationic part, i.e. the imidazolium based or the pyridinium based, is discussed well. The ILs containing the catalyst can be readily separated from the reaction products and recovered in very high purity for direct reuse, up to six cycles.

Novel tetrahydroisoquinoline based organocatalysts for asymmetric Diels-Alder reactions: Insight into the catalytic mode using ROESY NMR and DFT studies

For the first time an organocatalyst bearing a secondary nitrogen within a cyclohexane ring has been evaluated in the asymmetric Diels-Alder reaction. This organocatalyst is also the first of its kind based on a (1R,3S)-6,7-dimethoxy- 1-phenyl-1,2,3,4-tetrahydroisoquinoline backbone. These catalysts were tested over a range of dienes and dienophiles and displayed promising chemical conversions of up to 100% with up to 64% ee with triflic acid as the cocatalyst. Density functional theory computational studies and 2D NMR spectroscopy were used to determine the structure of the intermediate iminium ion formed between the most efficient catalyst and cinnamaldehyde. The reaction profile for each of the four possibilities in this reaction were calculated and it was found that the iminium intermediate leading to the major product is higher in energy but kinetically preferred. The activation energies of all possible reaction paths were calculated and the results correlated with the observed products. These experiments revealed that the presence of both (E)- and (Z)-isomers of the cinnamaldehyde were contributing factors for the low enantioselectivity of the reaction products.

Taming the silylium ion for low-temperature diels-alder reactions

Some like it hot: A novel silicon-based Lewis acid having a trivalent silicon cation stabilized by an electron-rich transition metal as the "hot" Lewis acidic site catalyzes challenging Diels-Alder reactions at low temperatures with excellent reaction rat