36794-64-6

Upstream product

• 19910-30-6 2,3,3-Trimethylbuttersaeure-methylester 
• 74669-71-9 (R)-2,3,3-Trimethylbutylamin 
• 75-97-8 3,3-dimethyl-butan-2-one 
• 558-37-2 tert-butylethylene 
• 124-38-9 carbon dioxide 
• 4957-78-2 3-bromo-4,4-dimethylpentan-2-one 
• 590-50-1 4,4-dimethyl-pentan-2-one 
• 10250-48-3 methyl 3,3-dimethylbutyrate 
• 201230-82-2 carbon monoxide 
• 50-00-0 formaldehyd 
• 513-35-9 2-methyl-but-2-ene 
• 75-24-1 trimethylaluminum 
• 594-56-9 2,2,3-trimethylbut-1-ene 

Downstream Products

• 594-56-9 2,2,3-trimethylbut-1-ene 
• 76698-22-1 2,3,3-Trimethyl-N-(2,4,6-trimethylphenyl)butanamid 
• 76698-21-0 N-(2,6-Dimethylphenyl)-2,3,3-trimethylbutanamid 
• 186029-85-6 Toluene-4-sulfonic acid 2,3,3-trimethyl-butyl ester 
• 71640-85-2 2,3,3-trimethylbutanal 

Relevant academic research and scientific papers

Acid-Promoted Hydroformylative Synthesis of Alcohol with Carbon Dioxide by Heterobimetallic Ruthenium-Cobalt Catalytic System

The acid-aided heterobimetallic ruthenium-cobalt catalytic system for the reductive hydroformylation with carbon dioxide was established. Various alkenes, including waste from biomass and petroleum industry, could be upgraded to valuable alcohols with this protocol. Acid-promoted reverse water-gas shift (RWGS), thereby accelerating the hydroformylative synthesis of alcohol. The theoretical computations revealed that acid promoted RWGS by facilitating the dehydroxylation of ruthenium hydroxy carbonyl intermediate.

Chiral propargylic cations as intermediates in SN1-type reactions: Substitution pattern, nuclear magnetic resonance studies, and origin of the diastereoselectivity

Nine propargylic acetates, bearing a stereogenic center (-C*HXR 2) adjacent to the electrophilic carbon atom, were prepared and subjected to SN1-type substitution reactions with various silyl nucleophiles employing bismuth trifluoromethanesulfonate [Bi(OTf)3] as the Lewis acid. The diastereoselectivity of the reactions was high when the alkyl group R2 was tertiary (tert-butyl), irrespective of the substituent X. Products were formed consistently with a diastereomeric ratio larger than 95:5 in favor of the anti-diastereoisomer. If the alkyl substitutent R2 was secondary, the diastereoselectivity decreased to 80:20. The reaction was shown to proceed stereoconvergently, and the relative product configuration was elucidated. The reaction outcome is explained by invoking a chiral propargylic cation as an intermediate, which is preferentially attacked by the nucleophile from one of its two diastereotopic faces. Density functional theory (DFT) calculations suggest a preferred conformation in which the group R2 is almost perpendicular to the plane defined by the three substituents at the cationic center, with the nucleophile approaching the electrophilic center opposite to R2. Transition states calculated for the reaction of allyltrimethylsilane with two representative cations support this hypothesis. Tertiary propargylic cations with a stereogenic center (-C* HXR2) in the α position were generated by ionization of the respective alcohol precursors with FSO3H in SO2ClF at -80 C. Nuclear magnetic resonance (NMR) spectra were obtained for five cations, and the chemical shifts could be unambiguously assigned. The preferred conformation of the cations as extracted from nuclear Overhauser experiments is in line with the preferred conformation responsible for the reaction of the secondary propargylic cations.

Catalytic asymmetric reductive amination of aldehydes via dynamic kinetic resolution

A novel organocatalytic asymmetric reductive amination of aldehydes has been developed. Treating racemic α-branched aldehydes with p-anisidine and a Hantzsch ester in the presence of our previously developed phosphoric acid catalyst, TRIP, gave β-branched secondary amines in excellent yields and enantioselectivities via an efficient dynamic kinetic resolution. The process is applicable to several different aromatic aldehydes and amines but gives slightly reduced enantiomeric ratios with aliphatic aldehydes. Copyright

Radical deuteration of α-selenylated-β-silylsulfoxides

The deuteration of α-selenylated-β-silylsulfoxides and α-selenylated-β-tert-butylsulfoxides has been shown to lead, with good levels of diastereocontrols to the formation of syn isomers irrespective of the stereochemistry of the sulfinyl precursors. Our results have been rationalized using transition state models which parallel the Felkin-Anh model.

Direct formation of alcohols by hydrocarbonylation of alkenes under mild conditions using rhodium trialkylphosphine catalysts

The complex [RhH(PEt3)3] catalysed the hydroformylation of hex-1-ene to heptanal and 2-methylhexanal in toluene, but heptanol and 2-methylhexanol were significant products in tetrahydrofuran especially over long reaction times (16 h). In protic solvents only alcohols were produced even after short reaction times. The reactions are very rapid and also occur readily with alkenes such as hex-2-ene, propene, ethene, styrene and 3,3-dimethylbutene. The highest rates observed are for ethene (54 000 turnovers h-1) and the products in all cases are alcohols. Other phosphines containing primary alkyl groups also produced alcohols, but in contrast reactions in ethanol using rhodium complexes containing PPh3, PPh2Et, PPhEt2 or PPri3 produced significant amounts of aldehydes and/or acetals whilst Me2PCH2CH2PMe2 inhibited the reaction. The NMR studies showed that species present in equilibrium in ethanol solution are [RhH(CO)(PEt3)3], [RhH(CO)2(PEt3)2], [Rh2(CO)4(PEt3)4], [Rh2(CO)2(PEt3)6] and PEt3 but that [RhH(CO)(PEt3)3] predominates under the catalytic conditions. Reactions carried out under D2-CO in EtOH produced 90% BuCHDCH2CD2OH/D and 10% BuCHDCH2CHDOH/D but hydrogenation of heptanal under the same conditions gave a mixture of C6H13CHDOH/D (39%) and C6H13CH2OH/D (61%). These results are interpreted to indicate that the alcohols produced from hex-1-ene are primary reaction products and not produced via intermediate aldehydes. A new mechanism for this direct hydrocarbonylation is proposed in which the key acyl intermediate becomes protonated by the alcoholic solvent because of the high electron density it bears as a result of the presence of the electron-donating trialkylphosphines. Oxidative addition of H2 followed by two H-atom transfers leads directly to the alcohol. High pressure NMR studies showed that [Rh{C(O...HOEt)Et}(CO)2(PEt3)2] is present during catalytic hydrocarbonylation of ethene in ethanol. Two different cycles are proposed to explain the products obtained from the catalytic reaction of heptanal with D2-CO. Again, protonation, this time of the metal, appears to be important.

Diastereoselectivity of the thio-Claisen rearrangement of acyclic precursors bearing a chiral centre adjacent to carbon 6

A number of chiral allylic alcohols have been prepared and submitted to a Mitsunobu reaction with dithioacetic acid. Allyl dithioesters were deprotonated by LDA at -30°C and resulting enethiolates were quenched with iodomethane to afford quantitatively S-

DIASTEREOFACIAL SELECTIVITY VIA ALDOL REACTIONS USING ETHYL DITHIOACETATE AND ETHYL DITHIOPROPIONATE ENOLATES

The lithium enolate of ethyl dithioacetate reacts with α-methyl aldehydes to yield the aldol products in which the syn configuration in the positions β and γ to the thiocarbonyl of the product is favored over the anti configuration.This selectivity is solvent-dependent, and is enhanced at lower temperatures.In most cases, syn:anti product ratios obtained under these conditions varied from 57:43 to >99:1, depending upon the structure of the α-methyl aldehyde.When the lithium enolate of ethyl dithiopropionate was allowed to react with α-methyl aldehydes, only two out of the four possible diastereomers were detected in the product mixtures.

Reactions of the Formaldehyde-Trimethylaluminum Complex with Alkenes

Reaction of CH2O*Me3Al with electron-rich alkenes gives a zwitterion that reacts further to give homoallylic alcohols (ene adducts), allylic alcohols, and the product of cis addition of a hydroxymethyl and a methyl group to the double bond.The stereochemistry and effect of alkene structure on the nature of the reaction are examined.

Stereochemistry of Addition to the Carbonyl Group. Part 17. Study of the Factors affecting Asymmetric Induction in Condensation Reactions of Methyl- and Phenyl-magnesium Bromide with Chiral Carbonyl Compounds

The dependence of the stereoselectivity upon the nature of the chiral carbonyl compound , the solvent, and the concentration ofthe reactive species for various condensation reactions of phenyl- and methyl-magnesium bromide at 30 degC is reported.The stereochemical results have been interpreted on the basis of the generalized Curtin-Hammett principle and according to a trigonal-type transition state (Perez-Ossorio model).No effect of the concentration of the reactive species on the product ratio was observed.An unexpected influence of the solvent was observed in the condensation of (4) with phenylmagnesium bromide.A good linear correlation between stereoselectivity and the ET parameter of the solvent was obtained.The explanation offered here takes into account the steric selection of the transition states and a further differentiating effect of the solvent polarity on them.A slight influence of solvent polarity on reactions of (5) with Grinard reagents was also noticed.

Cyclopropanimines, V. - Ring-substituted Cyclopropanimines from α-Bromoketimines

Good yields of N-alkyl- and N-arylcyclopropanimines 9 are obtained from the α-bromoketimines 8 in a 1,3-elimination of hydrogen bromide by means of an excess of potassium tert-butoxide in tetrahydrofuran.The α-bromoimine 14 forms the imine 15 derived from bicyclohexane.In part, the limitations of this 1,3-elimination can be traced back to an unsufficient acidity of the α'-protons of the α-bromoimines.All isolated cyclopropanimines are colorless, in vacuo distillable oils or low-melting crystals.Their stability parallels the size of the nitrogen subtituent.As shown by their 1H- and 13C-NMR spectra as well as the measurement of the ASIS and the temperature dependence of the 1H-NMR spectra the cyclopropanimines 9 exist as mixtures of (E,Z)-diastereomers.The (E)/(Z) ratio of the diastereomers increases with increasing size of the nitrogen substituent.According to its 13C-NMR spectrum, the bicyclohexanimine 15 prefers the boat conformation.The IR, UV, 1H-, and 13C-NMR spectra of the cyclopropanimines are compared to those of other heteromethylenecyclopropanes and of acyclic compounds.The main fragmentation paths in the mass spectrometer do not correspond to the thermal decomposition of the cyclopropanimines into isocyanides and alkenes.