7332-96-9

Usage

Physical state

Volatile, colorless liquid

Uses

a. Flavoring agent in food and beverages
b. Production of fragrances
c. Solvent in various industrial applications

Taste

Buttery and creamy

Health concerns

a. Respiratory problems
b. Classified as a respiratory irritant
c. Potential to cause lung damage and other health issues in workers regularly exposed

Regulatory efforts

Efforts to regulate and reduce the use of 1,2-butanedione in various industries due to health concerns.

Upstream product

• 3282-30-2 pivaloyl chloride 
• 14491-02-2 2,2-dimethyl-3-phenyl-2H-azirine 
• 93-58-3 benzoic acid methyl ester 
• 201230-82-2 carbon monoxide 
• 594-19-4 tert.-butyl lithium 
• 598-98-1 Methyl pivalate 
• 591-51-5 phenyllithium 
• 16474-43-4 pivalic acid tert-butyl ester 
• 13988-67-5 benzoylpivaloylmethane 
• 591-50-4 iodobenzene 
• 32398-67-7 4,4-dimethyl-1-phenyl-1-pentyn-3-one 
• 17475-11-5 1-phenyl-4,4-dimethylpent-2-yn-1-one 
• 4250-82-2 (3,3-dimethyl-but-1-ynyl)benzene 
• 917-92-0 3,3-Dimethylbut-1-yne 

Downstream Products

• 188617-02-9 2-hydroxy-3,3-dimethyl-2-phenyl-butyric acid 
• 15034-12-5 2-tert-butyl-3-phenyl-quinoxaline 
• 1452219-69-0 1-hydroxy-3,3-dimethyl-1-phenyl-1-(p-tolyl)butan-2-one 
• 6721-67-1 tert-butyl benzyl ketone 

Relevant academic research and scientific papers

Phosphorus(III)-Mediated, Tandem Deoxygenative Geminal Chlorofluorination of 1,2-Diketones

Tetrasubstituted carbon containing two different halogen substituents was constructed in a single-step operation by utilizing the carbene-like reactivity of dioxaphospholene through the tandem reaction of electrophilic and nucleophilic halogenating reagents. It was crucial to devise non-dealkylatable phosphoramidite, which enabled the efficient formation of geminal chlorofluorides from various 1,2-diketones with (PhSO2)2NF and n-Bu4NCl. In addition, selective functionalization of the chlorine substituent was demonstrated, and the absence of halogen scrambling was confirmed.

Copper/Iodine-Cocatalyzed C-C Cleavage of 1,3-Dicarbonyl Compounds Toward 1,2-Dicarbonyl Compounds

A new, general oxidative route to transformations of 1,3-dicarbonyl compounds to 1,2-dicarbonyl compounds by merging copper and I2 catalysis is described. This method is applicable to broad 1,3-dicarbonyl compounds, including 1,3-diketones, 1,3-keto esters and 1,3-keto amides. Mechanistical studies show that the reaction is achieved via the C–C bond cleavage and CO release cascades.

Palladium-Catalyzed Oxidative C≡C Triple Bond Cleavage of 2-Alkynyl Carbonyl Compounds Toward 1,2-Dicarbonyl Compounds?

A new, general palladium-catalyzed oxidative strategy for the cleavage of the C≡C triple bond is presented. By employing PdCl2, CuBr2, TEMPO and air as the catalytic system and H2O as the carbonyl oxygen atom source, a wide range of 2-alkynyl carbonyl compounds, including 1,3-disubstituted prop-2-yn-1-ones, propiolamides and propiolates, lost an alkynyl carbon to access various 1,2-dicarbonyl compounds, e.g., 1,2-diones, 2-keto amides and 2-keto esters, through Wacker oxidation, intramolecular cyclization and C—C bond cleavage cascades.

Dimethyl Sulfoxide as an Oxygen Atom Source Enabled Tandem Conversion of 2-Alkynyl Carbonyls to 1,2-Dicarbonyls

A tandem transformation of 2-alkynyl carbonyl compounds by means of a CuBr2/I2/DMSO/water system is developed, enabling the fromation of various functionalized 1,2-dicarbonyl compounds, including 1,2-diketones, α-keto amides and α-keto ester. This Cu-promoted iodine-mediated tandem procedure employs DMSO as the oxygen atom source of the formed carbonyl group through iodonium ion formation, nucleophilic DMSO addition and C?C bond cleavage cascades. (Figure presented.).

Nature of the Nucleophilic Oxygenation Reagent Is Key to Acid-Free Gold-Catalyzed Conversion of Terminal and Internal Alkynes to 1,2-Dicarbonyls

2,3-Dichloropyridine N-oxide, a novel oxygen transfer reagent, allows the conductance of the gold(I)-catalyzed oxidation of alkynes to 1,2-dicarbonyls in the absence of any acid additives and under mild conditions to furnish the target species, including those derivatized by highly acid-sensitive groups. The developed strategy is effective for a wide range of alkyne substrates such as terminal- and internal alkynes, ynamides, alkynyl ethers/thioethers, and even unsubstituted acetylene (40 examples; yields up to 99%). The oxidation was successfully integrated into the trapping of reactive dicarbonyls by one-pot heterocyclization and into the synthesis of six-membered azaheterocycles. This synthetic acid-free route was also successfully applied for the total synthesis of a natural 1,2-diketone.

Electrochemical synthesis of 1,2-diketones from alkynes under transition-metal-catalyst-free conditions

We report an electrochemical protocol for the direct oxidation of internal alkynes in air to provide 1,2-diketones. A variety of functional groups and heterocycle-containing substrates can be tolerated well under mild conditions.

Diphenylparabanic acid as a synthon for the synthesis of α-diketones and α-ketocarboxylic acids

Diphenylparabanic acid was found to react with >2 equiv of organolithiums at -78 °C to effectively give the corresponding symmetrical α-diketones. However, upon treatment with 1 equiv of organolithium, the parabanic acid gave mainly 5-substituted 5-hydroxyimidazolidine-2,4-diones. On the other hand, Grignard reagents were less reactive toward the parabanic acid at low temperature, and selectively gave the corresponding 5- hydroxyimidazolidine-2,4-diones even if more than 1 equiv of the reagents was used. A tandem process in which the parabanic acid was first reacted with a Grignard reagent and then reacted in one-pot with an organolithium effectively gave the unsymmetrical α-diketone. 5-Substituted 5-hydroxyimidazolidine-2, 4-diones were useful as versatile precursors for preparing α- ketocarboxylic acids as well as unsymmetrical α-diketones.

Ruthenium-catalyzed alkyne oxidation with part-per-million catalyst loadings

Using a catalytic system of the (cymene)ruthenium dichloride dimer, [Ru(cymene)Cl2]2, (0.001 mol%) and iodine (10 mol%), a variety of alkynes bearing different functional groups were oxidized with tert-butyl hydroperoxide (TBHP; 70% solution in water) under mild conditions to give 1,2diketones in good to excellent yields. Two noteworthy features of the method are the extremely high catalyst productivity (TON up to 420,000) and scale-up to 1 mol. Preliminary mechanism investigations showed that iodonium ion and water were involved in the transformation.

One-Pot Synthesis of Unsymmetrical Ketones by the Reaction of Decacarbonyldimanganese with Two Kinds of Alkyllithiums

Decacarbonyldimanganese (Mn2(CO)10) is utilized as a phosgene equivalent for the one-pot preparation of unsymmetrical ketones. By a successive treatment of Mn2(CO)10 with two kinds of alkyllithiums, unsymmetrical ketones are obtained in high selectivity. Unsymmetrical α-diketones are generated when the above reaction is carried out in the presence of trimethyl phosphite and is quenched with N-bromosuccinimide.

Reactions and reactivity of acyloxycarbenes

Phenylacetoxycarbene, phenyl(pivaloyloxy)carbene, and phenyl(benzoyloxy)carbene, photolytically generated from diazirine precursors in pentane at 25°C, efficiently rearranged by 1,2-acyl migrations to give high yields of the appropriate 1,2-diketones. The kinetics of these rearrangements were determined by laser flash photolysis. Substituent effects on the acyl migrations and ab initio electronic structure calculations on ground state carbenes and transition states were employed to analyze the rearrangement mechanism. Additions of phenylacetoxycarbene to alkenes proceeded in good yields, in lieu of the 1,2-acyl shift; absolute rate constants were obtained for these reactions of the ambiphilic carbene. (Phenoxymethyl)acetoxycarbene gave only a 1,2-H shift; the potentially competitive 1,2-acetyl migration was suppressed.