67201-22-3

Upstream product

• 544-97-8 dimethyl zinc(II) 
• 60729-55-7 cis-methyl 5-acetoxycyclohex-3-enecarboxylate 
• 87802-98-0 cis-5-[(methoxycarbonyl)oxy]-3-cyclohexene-1-carboxylic acid methyl ester 
• 4771-80-6 1,2,5,6-tetrahydrobenzoic acid 
• 19914-92-2 (+/-)-4-iodo-6-oxabicyclo[3.2.1]octan-7-one 
• 4720-83-6 6-oxabicyclo<3.2.1>-oct-3-en-7-one 
• 54911-89-6 cis-methyl 5-hydroxycyclohex-3-enecarboxylate 
• 493-72-1 5-phenyl-cyclohexane-1,3-dione 
• 26114-87-4 cis-1,2,3,6-tetrahydro-[1,1'-biphenyl]-3-ol 
• 292638-85-8 acrylic acid methyl ester 
• 78-79-5 isoprene 
• 2004-70-8 1-methylbuta-1,3-diene 
• 78-94-4 methyl vinyl ketone 
• 504-60-9 penta-1,3-diene 

Downstream Products

• 7605-52-9 trans-3-methyl-1-methoxycarbonylcyclohexane 
• 7605-52-9 cis-3-methyl-1-methoxycarbonylcyclohexane 

Relevant academic research and scientific papers

Asymmetric palladium-catalyzed allylic alkylation using dialkylzinc reagents: A remarkable ligand effect

A serendipitously discovered palladium-catalyzed asymmetric allylic alkylation reaction with diorganozinc reagents, which displays broad functional group compatibility, is reported. This novel transformation hinges on a remarkable ligand effect which overrides the standard "umpolung" reactivity of allyl-palladium intermediates in the presence of dialkylzincs. Owing to its mild conditions, enantioselective allylic alkylations of racemic allylic electrophiles are possible in the presence of sensitive functional groups. Umpole-me-not: A serendipitously discovered palladium-catalyzed asymmetric allylic alkylation reaction with diorganozinc reagents displays broad functional group compatibility. This novel transformation hinges on a remarkable ligand effect which overrides the standard "umpolung" reactivity of allyl-palladium intermediates in the presence of dialkylzinc compounds.

Use of functionalized onium salts as a soluble support for organic synthesis

The invention relates to the use of a onium salt functionalized by at least one organic function, as a soluble support, in the presence of at least one organic solvent, for organic synthesis of a molecule, in a homogenous phase, by at least one transformation of said organic function. The onium salt enables the synthesized molecule to be released. The onium salt is present in liquid or solid form at room temperature and corresponds to formula A1+, X1?, wherein A1+ represents a cation and X1? represents an anion.

Mechanism of di-tert-butylsilylene transfer from a silacyclopropane to an alkene

Kinetic and thermodynamic studies of the reactions of cyclohexene silacyclopropane 1 and monosubstituted alkenes suggested a possible mechanism for di-tert-butylsilylene transfer. The kinetic order in cyclohexene silacyclopropane 1 and cyclohexene were de

Silica-Promoted Diels-Alder Reactions in Carbon Dioxide from Gaseous to Supercritical Conditions

Amorphous fumed silica (SiO2) was shown to increase yields and selectivities of several Diels-Alder reactions in gaseous and supercritical CO2. Pressure effects on the Diels-Alder reaction were explored using methyl vinyl ketone and penta-1,3-diene at 80°C. The selectivity of the reaction was not affected by pressure/ density. As pressure was increased, the yield decreased. At the reaction temperature, adsorption isotherms at various pressures were obtained for the reactants and the Diels-Alder adduct. As expected when pressure is increased, the ratio of the amount of reactants adsorbed to the amount of reactants in the fluid phase decreases, thus causing the yield to decrease. The Langmuir adsorption model fit the adsorption data. The Langmuir equilibrium partitioning constants all decreased with increasing pressure. The effect of temperature on adsorption was experimentally determined and traditional heats of adsorption were calculated. However, since supercritical CO2 is a highly compressible fluid, it is logical to examine the effect of temperature at constant density. In this case, entropies of adsorption were obtained. The thermodynamic properties that influence the real enthalpy and entropy of adsorption were derived. Methods of doping the silica and improving yields and selectivities were also explored.

Stereochemistry of the palladium-catalyzed allylic substitution: The synanti dichotomy in the formation of (π-allyl)palladium complexes and their equilibration

The mechanism of palladium(0)-catalyzed allylic substitution has been investigated with the aim of finding whether or not the intermediate (π-alryl)palladium complexes can arise in a syn fashion as an alternative to the well known anti-mechanism. Using (diphenylphosphino)acetate as a leaving group and stereochemically biased substrates 30b and 35b evidence for the syn stereochemistry has been acquired (30b → 31 and 35b → 36). This reversal of stereochemistry is facilitated by severe steric congestion in the starting allylic esters (which impairs the ordinary anti-mechanism) and is boosted by the pre-coordination of the Pd(0) reagent to the leaving group. The latter effect apparently lowers the activation entropy. With cyclohexene derivatives 10b, 18b, and 19b and acyclic substrate 25b, where steric hindrance does not operate, the anti-mechanism producing η3-complexes dominates even for (diphenylphosphino)acetates. At elevated temperature, rapid equilibration of η3-complexes (13 ? 14 and 20 ? 21) has been observed prior to the reaction with a nucleophile. This effect has been attributed to the presence of (diphenylphosphino)acetate ion acting as a ligand for palladium.

Studies of the Transition-state Structure by the Method of Volumetric Steric Effects. Part 4. Transition State in Diels-Alder Reactions of (E)-1-Alkyl(alkoxy)buta-1,3-dienes with Alkyl Acrylates

A method of studying transition-state structures by analysis of volumetric steric effects is proposed.The method is used to reveal features of the steric structure of the transition state in Diels-Alder reactions.The structure has been found to change from one approximating the structure of the prereactional complex to that resembling the half-chair adduct as the diene substituent changes from methyl to t-butyl.As this takes place, no intermediate half-boat adduct is formed.An increase in steric hindrance during the change in the substituent is regarded as the driving force responsible for the transition-state shift along the reaction co-ordinate.This is consistent with the Hammond postulate.The C=O and C=C groups of the dienophile in the endo-transition state are in the s-cis-conformation.

STUDIES OF COMPOUNDS IN THE MENTHANE SERIES. XIX. SYNTHESIS AND PROPERTIES OF TRANS-o-4-MENTHEN-8-OL AND STEREOISOMERIC o-5-METHEN-8-OLS

Trans-o-4-Menthen-8-ol and cis- and trans-o-5-menthen-8-ols have been prepared via the Diels-Alder reactions of 1,3-butadiene with crotonaldehyde in the presence of boron trifluoride etherate, and piperylene with methyl acrylate, respectively.The dehydration reactions of these alcohols have been studied in the presence of acetic anhydride and potassium bisulfate; the latter reagent demonstrates a high reaction selectivity.

HIGHLY REGIOSELECTIVE DIELS-ALDER REACTIONS OF 2-TRIMETHYLSILYLMETHYL- AND 2-TRIMETHYLSTANNYLMETHYL-1,3-BUTADIENE

2-Trimethylsilylmethyl and 2-trimethylstannylmethyl-1,3-butadiene undergo facile cycloaddition with dienophiles, and show high regioselectivity with unsymmetrical dienophiles.