17339-96-7

Upstream product

• 57-60-3 piruvate 
• 765-87-7 cyclohexane-1,2-dione 
• 874-23-7 2-acetylcyclohexanone 
• 115-22-0 3-Hydroxy-3-methyl-2-butanone 
• 113-24-6 sodium pyruvate 

Relevant academic research and scientific papers

Structural and Mutagenesis Studies of the Thiamine-Dependent, Ketone-Accepting YerE from Pseudomonas protegens

A wide range of thiamine diphosphate (ThDP)-dependent enzymes catalyze the benzoin-type carboligation of pyruvate with aldehydes. A few ThDP-dependent enzymes, such as YerE from Yersinia pseudotuberculosis (YpYerE), are known to accept ketones as acceptor substrates. Catalysis by YpYerE gives access to chiral tertiary alcohols, a group of products difficult to obtain in an enantioenriched form by other means. Hence, knowledge of the three-dimensional structure of the enzyme is crucial to identify structure–activity relationships. However, YpYerE has yet to be crystallized, despite several attempts. Herein, we show that a homologue of YpYerE, namely, PpYerE from Pseudomonas protegens (59 % amino acid identity), displays similar catalytic activity: benzaldehyde and its derivatives as well as ketones are converted into chiral 2-hydroxy ketones by using pyruvate as a donor. To enable comparison of aldehyde- and ketone-accepting enzymes and to guide site-directed mutagenesis studies, PpYerE was crystallized and its structure was determined to a resolution of 1.55 ?.

Enzymatic Chemoselective Aldehyde-Ketone Cross-Couplings through the Polarity Reversal of Methylacetoin

Abstract The thiamine diphosphate (ThDP) dependent enzyme acetoin:dichlorophenolindophenol oxidoreductase (Ao:DCPIP OR) from Bacillus licheniformis was cloned and overexpressed in Escherichia coli. The recombinant enzyme shared close similarities with the acetylacetoin synthase (AAS) partially purified from Bacillus licheniformis suggesting that they could be the same enzyme. The product scope of the recombinant Ao:DCPIP OR was expanded to chiral tertiary α-hydroxy ketones through the rare aldehyde-ketone cross-carboligation reaction. Unprecedented is the use of methylacetoin as the acetyl anion donor in combination with a range of strongly to weakly activated ketones. In some cases, Ao:DCPIP OR produced the desired tertiary alcohols with stereochemistry opposite to that obtained with other ThDP-dependent enzymes.

Highly efficient C-H hydroxylation of carbonyl compounds with oxygen under mild conditions

A transition-metal-free Cs2CO3-catalyzed α-hydroxylation of carbonyl compounds with O2 as the oxygen source is described. This reaction provides an efficient approach to tertiary α-hydroxycarbonyl compounds, which are highly valued chemicals and widely used in the chemical and pharmaceutical industry. The simple conditions and the use of molecular oxygen as both the oxidant and the oxygen source make this protocol very environmentally friendly and practical. This transformation is highly efficient and highly selective for tertiary C(sp3)-H bond cleavage. OH, so simple! A transition-metal-free Cs2CO 3-catalyzed α-hydroxylation of carbonyl compounds with O 2 provided a variety of tertiary α-hydroxycarbonyl compounds (see scheme; DMSO=dimethyl sulfoxide), which are widely used in the chemical and pharmaceutical industry. The simple conditions and the use of molecular oxygen as both the oxidant and the oxygen source make this protocol very efficient and practical.

Extended reaction scope of thiamine diphosphate dependent cyclohexane-1,2-dione hydrolase: From C-C bond cleavage to C-C bond ligation

ThDP-dependent cyclohexane-1,2-dione hydrolase (CDH) catalyzes the CC bond cleavage of cyclohexane-1,2-dione to 6-oxohexanoate, and the asymmetric benzoin condensation between benzaldehyde and pyruvate. One of the two reactivities of CDH was selectively knocked down by mutation experiments. CDH-H28A is much less able to catalyze the CC bond formation, while the ability for CC bond cleavage is still intact. The double variant CDH-H28A/N484A shows the opposite behavior and catalyzes the addition of pyruvate to cyclohexane-1,2-dione, resulting in the formation of a tertiary alcohol. Several acyloins of tertiary alcohols are formed with 54-94% enantiomeric excess. In addition to pyruvate, methyl pyruvate and butane-2,3-dione are alternative donor substrates for CC bond formation. Thus, the very rare aldehyde-ketone cross-benzoin reaction has been solved by design of an enzyme variant.

I2-catalyzed direct α-hydroxylation of β-dicarbonyl compounds with atmospheric oxygen under photoirradiation

An I2-catalyzed hydroxylation of β-dicarbonyl moieties using air as the oxidant under photoirradiation has been developed for the easy preparation of α-hydroxy-β-dicarbonyl compounds. The transformation was completed with only 1 mol % of I2. With α-unsubstituted malonates, the hydroxylated dimerization product was afforded as the predominant product along with a minor product, α,α-dihydroxyl malonate.

Catalytic oxidations of enolizable ketones using 2-alkylidene-4- oxothiazolidine vinyl bromide

Direct oxidation of enolizable ketones to α-hydroxy derivatives, vicinal dicarbonyls or tricarbonyl compounds has been achieved by a catalytic amount of 2-alkylidene-4-oxothiazolidine vinyl bromide in DMSO as a solvent. The yields range from moderate to good.

A simple and effective method for α-hydroxylation of β-dicarbonyl compounds using oxone as an oxidant without a catalyst

Oxone has been found to be a highly efficient reagent for the introduction of a hydroxy group at the α position of a variety of β-dicarbonyl compounds in the homogeneous solvent mixture of water and 1,4-dioxane at 60 °C. We have developed a simple and effective method for the α-hydroxylation of β-dicarbonyl compounds using Oxone as anoxidant in the homogeneous solvent mixture of water and 1,4-dioxane at 60 °C without a catalyst. Copyright

Novel oxygenations with IBX

Universal remedy: The α-hydroxylation of β-keto esters and a range of other suitably substituted carbonyl compounds can be effected in the presence of IBX (2-iodoxybenzoic acid). This novel reactivity underscores the importance of IBX as a universally applicable oxidizing agent.

Preparation of acyloins by cerium-catalyzed, direct hydroxylation of β-dicarbonyl compounds with molecular oxygen

We report the metal-catalyzed α-hydroxylation of a variety of cyclic and acyclic β-dicarbonyl compounds by molecular oxygen. The decisive advantage of this new method is the use of catalytic amounts of the nontoxic cerium salt CeCl3·7H2O in 2-propanol at ambient temperature. Most of the cyclic substrates 4a-4i give high yields of analytically pure products 5a-5i, and the workup procedure is simple filtration through silica gel. The oxidation of acyclic dicarbonyl compounds 4j-4p, however, is accompanied by side reactions and decomposition, reducing the yields of products 5j-5p significantly. A proposed mechanism is in agreement with experimental results, in particular the observed oxygen uptake. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.

Cerium-catalyzed α-oxidation of β-dicarbonyl compounds with molecular oxygen

β-Ketoesters and β-diketones are α-hydroxylated by molecular oxygen in the presence of 5 mol% CECl3-7 H2O in i-PrOH as solvent. The method is limited to substrates with an α-alkyl substituent. Optimal yields are achieved with cyclic