74636-51-4

Upstream product

• 13735-81-4 1-styrenyloxytrimethylsilane 
• 98-86-2 acetophenone 
• 70-11-1 α-bromoacetophenone 
• 721-04-0 2-phenoxy-1-phenylethanone 
• 17537-31-4 Acetophenone-methyl-d3 
• 536-74-3 phenylacetylene 
• 4636-16-2 iodoacetophenone 
• 60507-03-1 acetophenone-d1 
• 78793-82-5 (C₆H₅(O₂CCH₃)C₂Tl(O₂CCH₃))2 

Downstream Products

• 17537-31-4 Acetophenone-methyl-d3 

Relevant academic research and scientific papers

Imidazolidene carboxylate bound MBPh4 complexes (M = Li, Na) and their relevance in transcarboxylation reactions

Combination of 1,3-bis(2,6-diisopropylphenyl)imidazolum-2-carboxylate (IPrCO2) with the Lewis acids MBPh4, where M = Li or Na, provided two separate complexes. The crystal structures of these complexes revealed that coordination to NaBPh4 yielded a dimeric species, yet coordination of IPrCO2 with LiBPh4 yielded a monomeric species. Combination of 1,3-bis(2,4,6-trimethylphenyl)imidazolum-2-carboxylate (IMesCO2) with LiBPh4 also afforded a dimeric species that was similar in global structure to that of the IPrCO2+NaBPh 4 dimer. In all three cases, the cation of the organic salt was coordinated to the oxyanion of the zwitterionic carboxylate. Thermogravimetric analysis of the crystals demonstrated that decarboxylation occurred at lower temperatures than the decarboxylation temperature of the parent NHC·CO2 (NHC = N-heterocyclic carbene). Kinetic analysis of the transcarboxylation of IPrCO2 to acetophenone with NaBPh 4 to yield sodium benzoylacetate was performed. First-order dependences were observed for IPrCO2 and acetophenone, whereas zero -order dependence was observed for NaBPh4. Direct dicarboxylation was observed when ItBuCO2 was added to MeCN in the absence of added MBPh4.

Synthesis and application of a novel bis-1,2,3-triazole ligand containing a 2,2'-bipyrrolidine core

Herein, we describe the synthesis of a novel bis-1,2,3-triazole ligand which contains an internal N-alkylated 2,2'-bipyrrolidine linker. By using simple starting materials, the ligand could be generated in good yield through several synthetic steps. To investigate the potential for the application of this ligand in transition metal catalysis, we generated a bis-Au(I) complex in nearly quantitative yield and examined its reactivity in the context of alkyne hydration. Both alkyl and aryl terminal alkynes could be efficiently converted to their corresponding ketones in nearly quantitative yields with only 1% catalyst loading under mild conditions.

Tropylium Ion Catalyzes Hydration Reactions of Alkynes

The hydration of alkynes is one of the most atom-economic and versatile synthetic protocols to access carbonyl compounds. This fundamental reaction, however, often requires transition-metal catalysts or harsh reaction conditions to promote the addition of water to the carbon–carbon triple bond. In this work, it is demonstrated that the non-benzenoid aromatic tropylium ion can be used as an organic Lewis acid promoter for the hydration of alkynes under simple reaction conditions with excellent outcomes.

Catalytic C-O bond cleavage of 2-aryloxy-1-arylethanols and its application to the depolymerization of lignin-related polymers

A ruthenium-catalyzed, redox neutral C-O bond cleavage of 2-aryloxy-1-arylethanols was developed that yields cleavage products in 62-98% isolated yield. This reaction is applicable to breaking the key ethereal bond found in lignin-related polymers. The bond transformation proceeds by a tandem dehydrogenation/reductive ether cleavage. Initial mechanistic investigations indicate that the ether cleavage is most likely an organometallic C-O activation. A catalytic depolymerization of a lignin-related polymer quantitatively yields the corresponding monomer with no added reagent.

On the mechanism of ylide-mediated cyclopropanations: Evidence for a proton-transfer step and its effect on stereoselectivity

In this paper, we describe studies on the cyclopropanation of Michael acceptors with chiral sulfur ylides. It had previously been found that semi-stabilized sulfonium ylides (e.g., Ph-stabilized) reacted with cyclic and acyclic enones and substituted acrylates with high ee and that stabilized sulfonium ylides (e.g., ester-stabilized) reacted with cyclic enones again with high ee. The current study has focused on the reactions of stabilized sulfonium ylides with acyclic enones which unexpectedly gave low ee. Furthermore, a clear correlation of ee with ylide stability was observed in reactions with methyl vinyl ketone (MVK): ketone-stabilized ylide gave 25% ee, ester-stabilized ylide gave 46% ee, and amide-stabilized ylide gave 89% ee. It is believed that following betaine formation an unusual proton transfer step intervenes which compromises the enantioselectivity of the process. Thus, following addition of a stabilized ylide to the Michael acceptor, rapid and reversible intramolecular proton transfer within the betaine intermediate, prior to ring closure, results in an erosion of ee. Proton transfer occurred to the greatest extent with the most stabilized ylide (ketone). When the same reactions were carried out with deuterium-labeled sulfonium ylides, higher ees were observed in all cases since proton/deuteron transfer was slowed down. The competing proton transfer or direct ring-closure pathways that are open to the betaine intermediate apply not only to all sulfur ylides but potentially to all ylides. By applying this model to S-, N-, and P-ylides we have been able to rationalize the outcome of different ylide reactions bearing a variety of substituents in terms of chemo- and enantioselectivity.

Triazabicyclodecene: An effective isotope exchange catalyst in CDCl 3

(Chemical Equation Presented) We describe the first effective H/D exchange reaction with acidic substrates in CDCl3 at room temperature. The particularly mild reaction conditions involved (solvent, base, and temperature) allow the chemoselective deuteration of ketones over esters. An NMR study was conducted with the aim of rationalizing the results obtained in the presence of TBD as catalyst.

Investigations into the regioselective deuteriation of enolates derived from silyl enol ethers and enolacetates

Results are reported on the regioselective C-deuteriation of a series of enolates derived from the addition of MeLi to the related enolacetate and silyl enol ether and discussed in terms of the similarity between these methods; comments are made on the possible role of the additive, lithium tertbutoxide. Copyright

Formation of cyclopent[a]indene and acenaphthylene from allyl esters of biphenyl mono- and di-carboxylic acids and from biphenyl dicarboxylic anhydrides on flash vacuum pyrolysis at 1000-1100°C

Flash vacuum pyrolysis at 1000-1100°C of the allyl esters of the three isomeric biphenylcarboxylic acids, of the allyl esters of the 12 biphenyldicarboxylic acids and of the three biphenyldicarboxylic anhydrides gave pyrolysates which were examined by 1H n.m.r. spectroscopy at temperatures below -50°C. In all cases the spectra showed the presence of cyclopent[a]indene and acenaphthylene together with other products. Possible mechanisms for these ring contraction and cyclization processes are discussed and the results of pyrolyses of [2,3-13C2]biphenyl-2,3-dicarboxylic anhydride, and [3,4-13C2]-and (2-2H1)-biphenyl-3,4-dicarboxylic anhydrides are reported.

Secondary deuterium isotope effects for enolization reactions

Secondary α- and β-deuterium isotope effects for enolization reactions and equilibria have been determined by ab initio calculations, 1H NMR spectroscopy, and triton exchange kinetics. Kinetic and equilibrium α-deuterium isotope effects for hydroxide ion-catalyzed enolization of acetaldehyde calculated by ab initio methods are normal and depend on the orientation of the secondary hydrogen with respect to the carbonyl group. The computed transition state structure indicates a small degree of bond rehybridization at the transition state. Experimentally measured secondary isotope effects on the deuteroxide ion-catalyzed proton exchange of acetophenone are k(H)/k(D) = 1.08 ± 0.07 for α-CH3 exchange and k(H)/k(D) = 0.96 ± 0.08 for α-CH2D exchange. For α-CH2T exchange in water, the corresponding secondary isotope effect is k(H)/k(D) = 1.06 ± 0.02, assuming the rule of the geometric mean is valid. These effects are smaller than the calculated equilibrium isotope effect for formation of the enolate ion-water complex: K(H)/K(D) = 1.11-1.22 at the MP2 level. The normal kinetic isotope effects are smaller than might be expected due to a loss in hyperconjugation of the out-of-plane C-H bond and a lag in structural reorganization that contributes to the intrinsic barrier for proton transfer from carbon. Ionization of protonated acetone gives rise to an inverse secondary isotope effect of 0.97/D for the C-L bond adjacent to the carbonyl group and is consistent with a loss in hyperconjugation upon formation of the neutral ketone.

Rearrangements Accompanying the Fragmentation of Ionized 1-Phenylalkan-1-ols

Some aspects of the fragmentation sequence of 1-phenylalkan-1-ols(C6H5CH(OH)R), which consists of the loss of R(.) followed by the elimination of CO and subsequently of H2, are discussed.Labelling studies and collision activation data of reference compounds allow a mechanism to be proposed for this rearrangement.