Monocarbonyl Compounds Research Articles

Qualitative and Quantitative Profiling of Fructose Degradation Products Revealed the Formation of Thirteen Reactive Carbonyl Compounds and Higher Reactivity Compared to Glucose.

Fructose occurs in foods and as a metabolite in vivo. It can be degraded, leading to the formation of reactive carbonyl compounds, which may influence food properties and have an impact on health. The present study performed an in-depth qualitative and quantitative profiling of fructose degradation products. Thus, the α-dicarbonyl compounds 3-deoxyglucosone, glucosone, methylglyoxal, glyoxal, hydroxypyruvaldehyde, threosone, 3-deoxythreosone, and 1-desoxypentosone and the monocarbonyl compounds formaldehyde, acetaldehyde, glycolaldehyde, glyceraldehyde, and dihydroxyacetone were detected in fructose solutions incubated at 37 °C. Quantitative profiling after 7 days revealed 4.6-271.6-fold higher yields of all degradation products from fructose compared to glucose. Except for 3-deoxyglucosone, the product formation appeared to be metal dependent, indicating oxidative pathways. CaCl2 and MgCl2 partially reduced fructose degradation. Due to its high reactivity compared to glucose, particularly toward metal-catalyzed pathways, fructose may be a strong contributor to sugar degradation and Maillard reaction in foods and in vivo.

Advances in the Synthesis of Heterocycles with Two and Three Heteroatoms using Hydrazonoyl Halides

AbstractThe review covers the results of studies published in the literature on the use of hydrazonoyl halides in the synthesis of five‐ (pyrazoles, thiazoles, triazoles, oxa‐ and thiadiazoles), six‐ (oxa‐ and thiadiazines, indazoles, pyridazines, pyrazines, tetrazines) or seven‐membered (benzotriazepine) heterocycles. In the formation of these heterocycles, the main intermediate stage of the reaction is the in situ generation of nitrilimine, which enters into a cycloaddition reaction with substituted acetylenes (including in situ generated benzynes, naphthynes), allenes, activated olefins, anthranilic acid derivatives, organosulfur compounds (mercaptoaldehydes, mercaptocarboxylic acids) or with fused heterocycles. Examples are given of the formation of heterocycles by replacing the halogen atom from a hydrazonoyl halide molecule with a nucleophilic group, followed by exhaustive intramolecular cyclization into the target compound. There are discussions of reactions in which the cycloaddition of the nitrilimine to the in situ synthesized Knoevenagel condensation product (from CH‐acid compounds, such as di‐ and monocarbonyl compounds, dinitrile malonic acid) occurs, leading to spiro‐linked or conventional pyrazoles. Some syntheses of biologically active representatives are shown.

Preparation and Synthetic Applications of Five-to-Seven-Membered Cyclic α-Diazo Monocarbonyl Compounds.

The reactivity of cyclic α-diazo monocarbonyl compounds differs from that of their acyclic counterparts. In this review, we summarize the current literature available on the synthesis and synthetic applications of three major classes of cyclic α-diazo monocarbonyl compounds: α-diazo ketones, α-diazo lactones and α-diazo lactams.

Catalytic Deoxygenative Cyclopropanation of 1,2-Dicarbonyl or Monocarbonyl Compounds via Molybdenum Catalysis

AbstractThe cyclopropanation of alkenes through the transition-metal-catalyzed decomposition of diazo compounds is a powerful and straightforward strategy to produce cyclopropanes. Nevertheless, the appeal of further application of this strategy is tempered by the potentially explosive nature of the diazo substrates. Therefore, it is highly desirable to develop sustainable and operationally safe surrogates for diazo compounds. In this Synpacts article, we discuss recent advances on the cyclopropane syntheses through the catalytic cyclopropanation of alkenes and metal carbenes generated in situ from nondiazo precursors as well as highlight our recent progress on the unprecedented molybdenum-catalyzed deoxygenative cyclopropanation reaction of 1,2-dicarbonyl or monocarbonyl compounds.

Synthesis of Mono-Carbonyl Analogues of Curcumin Assisted by Microwave Irradiation

Mono-carbonyl compounds of curcumin, especially those containing hydroxy groups at the para position in the aromatic ring flanked by an electron withdrawing group (EWG) like chlorine, are known to have anti-inflammatory, antioxidant, and antibacterial activity. This study aims to synthesize mono-carbonyl compounds of curcumin with assisted microwave synthesis and determine its toxicity. The acute toxicity assay carried out on zebrafish larvae. The results showed that the synthesis of mono-carbonyl compounds of curcumin with assisted microwave synthesis gave clean products, faster reaction rates, more product yields, economical, and environmentally friendly. The optimal synthesis results obtained at 160Watt microwave radiation energy for 10 minutes. The acute toxicity assay of HGV-6, PGV-6, and GVT-6 compounds showed low toxicity to zebrafish larvae.

Molybdenum-Catalyzed Deoxygenative Cyclopropanation of 1,2-Dicarbonyl or Monocarbonyl Compounds.

The transition-metal-catalyzed cyclopropanation of alkenes by the decomposition of diazo compounds is a powerful and straightforward strategy to produce cyclopropanes, but is tempered by the potentially explosive nature of diazo substrates. Herein we report the Mo-catalyzed regiospecific deoxygenative cyclopropanation of readily available and bench-stable 1,2-dicarbonyl compounds, in which one of the two carbonyl groups acts as a carbene equivalent upon deoxygenation and engages in the subsequent cyclopropanation process. The use of a commercially available Mo catalyst afforded an array of valuable cyclopropanes with exclusive regioselectivity in up to 90 % yield. The synthetic utility of this method was further demonstrated by gram-scale syntheses, late-stage functionalization, and the cyclopropanation of a simple monocarbonyl compound. Preliminary mechanistic studies suggest that phosphine (or silane) acts as both a mild reductant and a good oxygen acceptor that efficiently regenerates the catalytically active Mo catalyst through reduction of the Mo-oxo complexes.

Molybdenum‐Catalyzed Deoxygenative Cyclopropanation of 1,2‐Dicarbonyl or Monocarbonyl Compounds

AbstractThe transition‐metal‐catalyzed cyclopropanation of alkenes by the decomposition of diazo compounds is a powerful and straightforward strategy to produce cyclopropanes, but is tempered by the potentially explosive nature of diazo substrates. Herein we report the Mo‐catalyzed regiospecific deoxygenative cyclopropanation of readily available and bench‐stable 1,2‐dicarbonyl compounds, in which one of the two carbonyl groups acts as a carbene equivalent upon deoxygenation and engages in the subsequent cyclopropanation process. The use of a commercially available Mo catalyst afforded an array of valuable cyclopropanes with exclusive regioselectivity in up to 90 % yield. The synthetic utility of this method was further demonstrated by gram‐scale syntheses, late‐stage functionalization, and the cyclopropanation of a simple monocarbonyl compound. Preliminary mechanistic studies suggest that phosphine (or silane) acts as both a mild reductant and a good oxygen acceptor that efficiently regenerates the catalytically active Mo catalyst through reduction of the Mo‐oxo complexes.

Solar light induced transformation mechanism of allyl alcohol to monocarbonyl and dicarbonyl compounds on different TiO2: A combined experimental and theoretical investigation

Enols are an important group of photochemical precursors of atmospheric carbonyl compounds. However, the transformation mechanism is not fully understood. In this study, the photo-induced transformation of a typical enol, allyl alcohol, to carbonyl compounds on TiO2 (P25) and aluminum reduced TiO2 (P25, rutile and anatase TiO2) were investigated. Intermediate results confirmed that a total of seven carbonyl compounds, including four monocarbonyl compounds (acetone, glycolaldehyde, 1,3-dihydroxyacetone and acrolein) and three dicarbonyl compounds (glyoxal, methylglyoxal and dimethylglyoxal), were formed on studied TiO2. This is the first time to report the transformation of allyl alcohol to dicarbonyl compounds on TiO2. The same byproducts formation indicated negligible effects of reduction treatment and crystal phase to the composition of carbonyl intermediates. However, the relative content ratio of dicarbonyl compounds to monocarbonyl ones on reduced P25 is ca. 4.1 times higher than that on P25, suggesting reduction treatment significantly accelerated the transformation of allyl alcohol or monocarbonyl compounds to dicarbonyl ones. Furthermore, both rutile and anatase crystal phases were found beneficial for the dicarbonyl compounds generation within enough reaction time, especially for anatase. The enhanced •OH was responsible for all accelerations. Furthermore, the intermediate results together with quantum chemical calculations confirmed that •OH addition and O2 oxidation preferred converting allyl alcohol to dicarbonyl compounds rather than monocarbonyl ones. The present work could provide a deep insight into the transformation of allyl alcohol to carbonyl compounds, and efficiently replenish atmospheric transformation fate of enols.

Gold‐Catalyzed Formal C−C Bond Insertion Reaction of 2‐Aryl‐2‐diazoesters with 1,3‐Diketones

The transition-metal-catalyzed formal C-C bond insertion reaction of diazo compounds with monocarbonyl compounds is well established, but the related reaction of 1,3-diketones instead gives C-H bond insertion products. Herein, we report a protocol for a gold-catalyzed formal C-C bond insertion reaction of 2-aryl-2-diazoesters with 1,3-diketones, which provides efficient access to polycarbonyl compounds with an all-carbon quaternary center. The aryl ester moiety plays a crucial role in the unusual chemoselectivity, and the addition of a Brønsted acid to the reaction mixture improves the yield of the C-C bond insertion product. A reaction mechanism involving cyclopropanation of a gold carbenoid with an enolate and ring-opening of the resulting donor-acceptor-type cyclopropane intermediate is proposed. This mechanism differs from that of the traditional Lewis-acid-catalyzed C-C bond insertion reaction of diazo compounds with monocarbonyl compounds, which involves a rearrangement of a zwitterion intermediate as a key step.

Enantioselective Direct Mannich‐Type Reactions Catalyzed by Frustrated Lewis Acid/Brønsted Base Complexes

AbstractAn enantioselective direct Mannich‐type reaction catalyzed by a sterically frustrated Lewis acid/Brønsted base complex is disclosed. Cooperative functioning of the chiral Lewis acid and achiral Brønsted base components gives rise to in situ enolate generation from monocarbonyl compounds. Subsequent reaction with hydrogen‐bond‐activated aldimines delivers β‐aminocarbonyl compounds with high enantiomeric purity.

Enantioselective Direct Mannich-Type Reactions Catalyzed by Frustrated Lewis Acid/Brønsted Base Complexes.

An enantioselective direct Mannich-type reaction catalyzed by a sterically frustrated Lewis acid/Brønsted base complex is disclosed. Cooperative functioning of the chiral Lewis acid and achiral Brønsted base components gives rise to in situ enolate generation from monocarbonyl compounds. Subsequent reaction with hydrogen-bond-activated aldimines delivers β-aminocarbonyl compounds with high enantiomeric purity.

Frustrated Lewis Acid/Brønsted Base Catalysts for Direct Enantioselective α-Amination of Carbonyl Compounds.

A method for enantioselective direct α-amination reaction catalyzed by a sterically "frustrated" Lewis acid/Brønsted base complex is disclosed. Cooperative functioning of the Lewis acid and Brønsted base components gives rise to in situ enolate generation from monocarbonyl compounds. Subsequent reaction with hydrogen-bond activated dialkyl azodicarboxylates delivers α-aminocarbonyl compounds in high enantiomeric purity.

Synthesis of 4-piperidone Based Curcuminoids with Anti-inflammatory and Anti-Proliferation Potential in Human Cancer Cell Lines.

A series of 4-piperidone based curcuminoids were synthesized and anticancer potential of these compounds was evaluated against human myeloid leukemia (KBM5) and colon cancer (HCT116) cell lines. Their anti-inflammatory potential was determined through the down-regulation of tumor necrosis factor (TNF)-α-induced nuclear factor (NF)-κB. All compounds, except one, were found to exhibit better cytotoxicity than curcumin at 5 μM. Furthermore, many compounds have shown good potential to inhibit the TNF-α-induced NF-κB activation. Docking study of the compounds with NF-κB revealed that the binding affinity of the compounds ranged from ‒9.0 to ‒6.5 kcal/mol with 0-8 H-bonds. It was also observed that amido-ether based mono-carbonyl compounds bound around the same region of NF-κB where polynucleotides are known to bind to exhibit their activity.

Arylation of diethyl malonate and ethyl cyanoacetate catalyzed by palladium/di-tert-butylneopentylphosphine

α-Arylated carbonyl derivatives are important structural motifs in many natural products and pharmaceutically active compounds. Although arylation of simple monocarbonyl compounds is a well-established methodology, metal-catalyzed arylation of β-dicarbonyl derivatives is significantly more challenging. The ability of β-dicarbonyl anions to bind to palladium in a κ2-O,O mode, rather than the κ1-C-bound mode required for bond formation, often results in the deactivation of catalyst systems. The C-bound form of the enolate can be favored through the use of sterically demanding ligands. Herein, we report that the sterically demanding di-tert-butylneopentylphosphine (DTBNpP) ligand in combination with Pd(dba)2 provides an effective catalyst for the coupling of aryl bromides and chlorides with diethyl malonate. The Pd/DTBNpP system also catalyzes the coupling of aryl bromides with ethyl cyanoacetate.

Synthesis of Highly Substituted Oxazoles through Iodine(III)-Mediated Reactions of Ketones with Nitriles

In the presence of trifluoromethanesulfonic acid (TfOH) or bis(trifluoromethane-sulfonyl)imide (Tf2NH), iodosobenzene (PhI=O) efficiently promoted the reactions of dicarbonyl compounds as well as monocarbonyl compounds with nitriles to give 2,4-disubstituted and 2,4,5-trisubstituted oxazole in a single step under the mild conditions.

Hydrogenation of BF 2 complexes with 1,3-dicarbonyl ligands

The catalytic hydrogenation (H 2, Pd/C) of a set of BF 2 complexes with a 1,3-dicarbonyl structural unit leading to monocarbonyl compounds has been studied. The transformation presented is general for the aryl-substituted derivatives and occurs under mild conditions (H 2, 1 bar, 25 °C) in methanol or THF.

Comparison of Isoelectronic Heterometallic and Homometallic Binuclear Cyclopentadienylmetal Carbonyls: The Iron–Nickel vs. the Dicobalt Systems

The heterometallic binuclear cyclopentadienylironnickel carbonyl compounds Cp2FeNi(CO)n (n =3 , 2, 1; Cp =η 5 -C5H5) have been studied by density functional theory (BP86) for comparison with the isoelectronic homometallic dicobalt derivatives Cp2Co2(CO)n. The FeNi tricarbonyl is shown to be the doubly bridged isomer Cp2Fe(CO)Ni(µ-CO)2 with an Fe– Ni distance of 2.455 A (BP86), in accord with experiment and in contrast to Cp2Co2(CO)3 where singly and triply bridged but not doubly bridged isomers are found. The dicarbonyl compounds Cp2FeNi(µ-CO)2 and Cp2Co2(µ-CO)2 both have analogous doubly bridged structures with M=M distances around 2.35 A, suggesting formal M=M double bonds. The monocarbonyl compounds have analogous singly bridged axial structures Cp2FeNi(µ-CO) and Cp2Co2(µ-CO) with

Reactions of Enamines with Selectfluor: A Straightforward Route to Difluorinated Carbonyl Compounds.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Reactions of Enamines with Selectfluor: A Straightforward Route to Difluorinated Carbonyl Compounds

[reaction: see text] Reactions of enamines, preformed from beta-dicarbonyl and monocarbonyl compounds, with Selectfluor (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) under mild conditions (triethylamine (TEA) or molecular sieves) easily led to the corresponding difluorinated carbonyl compounds in high yields.

Diphenylphosphide-Bridged Diiron Derivatives of [Fe2(η5-C5H5)2(μ-H)(μ-PPh2)(CO)2

The complex trans-[Fe2Cp2(μ-H)(μ-PPh2)(CO)2] is obtained in 91% yield by refluxing toluene solutions of [Fe2Cp2(CO)4] (Cp = η5-C5H5) and the secondary phosphine PPh2H. This compound isomerizes upon irradiation with visible−UV light under a CO atmosphere to yield cis-[Fe2Cp2(μ-H)(μ-PPh2)(CO)2]. The above hydride complexes react under photochemical conditions with 1 equiv of secondary phosphines PR2H (R = Et, Ph) to give the corresponding monocarbonyl compounds [Fe2Cp2(μ-PPh2)(μ-PR2)(μ-CO)] via the hydride intermediates [Fe2Cp2(μ-H)(μ-PPh2)(CO)(PR2H)] (detected and isolated for R = Et). Deprotonation of trans-[Fe2Cp2(μ-H)(μ-PPh2)(CO)2] with LiBu gives the binuclear anion [Fe2Cp2(μ-PPh2)(CO)2]-. This highly nucleophilic carbonylate reacts rapidly with [AuCl(PiPr3)] or MeI to give the corresponding gold diiron cluster [AuFe2Cp2(μ-PPh2)(CO)2(PiPr3)] or methyl derivative [Fe2Cp2(Me)(μ-PPh2)(μ-CO)(CO)2], respectively. Both hydrides cis- and trans-[Fe2Cp2(μ-H)(μ-PPh2)(CO)2] can be reversibly oxidized at low temperature to the corresponding cation radicals cis- and trans-[Fe2Cp2(μ-H)(μ-PPh2)(CO)2]+. At room temperature, however, the trans dicarbonyl cation isomerizes to its cis isomer, which in turn experiences a degradation process involving the reductive elimination of the bridging groups. The structures of the new complexes are analyzed on the basis of the corresponding IR and NMR (1H, 31P and 13C) spectroscopic data. The nature of the new radical cations is analyzed also on the basis of cyclic voltammetry and ESR measurements.