21048-30-6

Upstream product

• 98-88-4 benzoyl chloride 
• 326-06-7 1-Phenyl-4,4,4-trifluorobutane-1,3-dione 
• 62679-61-2 4,4-difluoro-1-phenyl-1,3-butanedione 
• 93-91-4 1-phenylbutan-1,3-dione 
• 100-52-7 benzaldehyde 
• 108-88-3 toluene 
• 100-51-6 benzyl alcohol 
• 492-70-6 1,2-diphenyl-1,2-ethanediol 
• 93-56-1 phenylethane 1,2-diol 
• 98-86-2 acetophenone 
• 65-85-0 benzoic acid 
• 476311-77-0 [Cu(1,10-phenanthroline)(2-benzoatophenylglyoxylate)2] 
• 622-42-4 1-nitro-1-phenylmethane 
• 100-39-0 benzyl bromide 

Downstream Products

• 100600-01-9 phenyl <(18)O>benzoate 
• 73007-61-1 C₁₀H₁₂O⁽¹⁸⁾O 
• 73007-65-5 C₁₀H₁₃N⁽¹⁸⁾O 
• 40095-13-4 O¹⁸-benzamide 
• 73007-66-6 C₁₃H₁₉N⁽¹⁸⁾O 
• 93-58-3 benzoic acid methyl ester 
• 21048-31-7 methyl [carbonyl-¹⁸O]benzoate 

Relevant academic research and scientific papers

Nitrogen Dioxide Catalyzed Aerobic Oxidative Cleavage of C(OH)–C Bonds of Secondary Alcohols to Produce Acids

Stable organic nitroxyl radicals are an important class of catalysts for oxidation reactions, but their wide applications are hindered by their steric hinderance, high cost, complex operation, and separation procedures. Herein, NO2 in DMSO is shown to effectively catalyze the aerobic oxidative cleavage of C(OH)?C bonds to form a carboxylic group, and NO2 was generated in situ by decomposition of nitrates. A diverse range of secondary alcohols were selectively converted into acids in excellent yields in this transition-metal-free system without any additives. Preliminary results also indicate its applicability to depolymerize recalcitrant macromolecular lignin. Detail studies revealed that NO2 from nitrates promoted the reaction, and NO2 served as hydrogen acceptor and radical initiator for the tandem oxidative reaction.

Regioselective aliphatic carbon-carbon bond cleavage by a model system of relevance to iron-containing acireductone dioxygenase

Mononuclear Fe(II) complexes ([(6-Ph2TPA)Fe(PhC(O)C(R)C(O)Ph)]X (3-X: R = OH, X = ClO4 or OTf; 4: R = H, X = ClO4)) supported by the 6-Ph2TPA chelate ligand (6-Ph2TPA = N,N-bis((6-phenyl-2-pyridyl)methyl)-N-(2-pyridylmethyl)amine) and containing a β-diketonate ligand bound via a six-membered chelate ring have been synthesized. The complexes have all been characterized by 1H NMR, UV-vis, and infrared spectroscopy and variably by elemental analysis, mass spectrometry, and X-ray crystallography. Treatment of dry CH3CN solutions of 3-OTf with O2 leads to oxidative cleavage of the C(1)-C(2) and C(2)-C(3) bonds of the acireductone via a dioxygenase reaction, leading to formation of carbon monoxide and 2 equiv of benzoic acid as well as two other products not derived from dioxygenase reactivity: 2-oxo-2- phenylethylbenzoate and benzil. Treatment of CH3CN/H2O solutions of 3-X with O2 leads to the formation of an additional product, benzoylformic acid, indicative of the operation of a new reaction pathway in which only the C(1)-C(2) bond is cleaved. Mechanistic studies show that the change in regioselectivity is due to the hydration of a vicinal triketone intermediate in the presence of both an iron center and water. This is the first structural and functional model of relevance to iron-containing acireductone dioxygenase (Fe-ARD′), an enzyme in the methionine salvage pathway that catalyzes the regiospecific oxidation of 1,2-dihydroxy-3-oxo-(S)- methylthiopentene to form 2-oxo-4-methylthiobutyrate. Importantly, this model system is found to control the regioselectivity of aliphatic carbon-carbon bond cleavage by changes involving an intermediate in the reaction pathway, rather than by the binding mode of the substrate, as had been proposed in studies of acireductone enzymes.

Functional models of α-keto acid dependent nonheme iron oxygenases: Synthesis and reactivity of biomimetic iron(II) benzoylformate complexes supported by a 2,9-dimethyl-1,10-phenanthroline ligand

Two biomimetic iron(II) benzoylformate complexes, [LFeII(BF) 2] (2) and [LFeII(NO3)(BF)] (3) (L is 2,9-dimethyl-1,10-phenanthroline and BF is monoanionic benzoylformate), have been synthesized from an iron(II)-dichloro complex [LFeIICl 2] (1). All the iron(II) complexes have been structurally and spectroscopically characterized. The iron(II) center in 2 is coordinated by a bidentate NN ligand (2,9-dimethyl-1,10-phenanthroline) and two monoanionic benzoylformates to form a distorted octahedral coordination geometry. One of the benzoylformates binds to the iron in 2 via both carboxylate oxygens but the other one binds in a chelating bidentate fashion via one carboxylate oxygen and the keto oxygen. On the other hand, the iron(II) center in 3 is ligated by one NN ligand, one bidentate nitrate, and one monoanionic chelating benzoylformate. Both iron(II) benzoylformate complexes exhibit the facial NNO donor environment in their solid-state structures. Complexes 2 and 3 are stable in noncoordinating solvents under an inert atmosphere, but react with dioxygen under ambient conditions to undergo oxidative decarboxylation of benzoylformate to benzoate in high yields. Evidence for the formation of an iron(IV)-oxo intermediate upon oxidative decarboxylation of benzoylformate was obtained by interception and labeling experiments. The iron(II) benzoylformate complexes represent the functional models of α-keto acid dependent oxygenases.

Catalytic O2activation with synthetic models of α-ketoglutarate dependent oxygenases

An iron complex bearing the facially capping tridentate 1,4,7-triazacyclononane ligand mimics structural and functional features of alpha-ketoglutarate (α-KG) dependent enzymes, and engages in enzyme-like catalytic O2 activation coupled to α-ketoacid decarboxylation, oxygenating sulfides. This system constitutes a rare case of non-enzymatic catalytic O2 activation, cycling between FeII and FeIV(O).

Phosphorus-Based Organocatalysis for the Dehydrative Cyclization of N-(2-Hydroxyethyl)amides into 2-Oxazolines

A metal-free, biomimetic catalytic protocol for the cyclization of N-(2-hydroxyethyl)amides to the corresponding 2-oxazolines (4,5-dihydrooxazoles), promoted by the 1,3,5,2,4,6-triazatriphosphorine (TAP)-derived organocatalyst tris(o-phenylenedioxy)cyclotriphosphazene (TAP-1) has been developed. This approach requires less precatalyst compared to the reported relevant systems, with respect to the phosphorus atom (the maximum turnover number (TON) ～30), and exhibits a broader substrate scope and higher functional-group tolerance, providing the functionalized 2-oxazolines with retention of the configuration at the C(4) stereogenic center of the 2-oxazolines. Widely accessible β-amino alcohols can be used in this approach, and the cyclization of N-(2-hydroxyethyl)amides provides the desired 2-oxazolines in up to 99% yield. The mechanism of the reaction was studied by monitoring the reaction using spectral and analytical methods, whereby an 18O-labeling experiment furnished valuable insights. The initial step involves a stoichiometric reaction between the substrate and TAP-1, which leads to the in situ generation of the catalyst, a catechol cyclic phosphate, as well as to a pyrocatechol phosphate and two possible active intermediates. The dehydrative cyclization was also successfully conducted on the gram scale.

A functional model for quercetin 2,4-dioxygenase: Geometric and electronic structures and reactivity of a nickel(II) flavonolate complex

Quercetin 2,4-dioyxgenase (QueD) has been known to catalyze the oxygenative degradation of flavonoids and quercetin. Recent crystallographic study revealed a nickel ion occupies the active site as a co-factor to support O2 activation and catalysis. Herein, we report a nickel(II) flavonolate complex bearing a tridentate macrocyclic ligand, [NiII(Me3-TACN)(Fl)(NO3)](H2O) (1, Me3-TACN = 1,4,7-trimethyl-1,4,7-triazacyclononane, Fl = 3-hydroxyflavone) as a functional model for QueD. The flavonolatonickel(II) complex was characterized by using spectrometric analysis including UV–vis spectroscopy, electrospray ionization mass spectrometer (ESI-MS), infrared spectroscopy (FT-IR) and 1H nuclear magnetic resonance spectroscopy (NMR). The single crystal X-ray structure of 1 shows two isomers with respect to the direction of a flavonolate ligand. Two isomers commonly are in the octahedral geometry with a bidentate of flavonolate and a monodentate of nitrate as well as a tridentate binding of Me3-TACN ligand. The spin state of 1 is determined to be a triplet state based on the Evans' method. Interestingly, electronic configuration of 1 from density functional theory (DFT) calculations revealed that the two singly occupied molecular orbitals (SOMOs) lie energetically lower than the highest (doubly) occupied molecular orbital (HOMO), that is so-called the SOMO-HOMO level inversion (SHI). The HOMO shows an electron density localized in the flavonolate ligand, indicating that flavonolate ligand is oxidized first rather than the nickel center. Thermal degradation of 1 resulted in the formation of benzoic acid and salicylic acid, which is attributed to the oxygenation of flavonolate of 1.

Bioinspired oxidation of oximes to nitric oxide with dioxygen by a nonheme iron(II) complex

The ability of two iron(II) complexes, [(TpPh2)FeII(benzilate)] (1) and [(TpPh2)(FeII)2(NPP)3] (2) (TpPh2 = hydrotris(3,5-diphenylpyrazol-1-yl)borate, NPP-H = α-isonitrosopropiophenone), of a monoanionic facial N3 ligand in the O2-dependent oxidation of oximes is reported. The mononuclear complex 1 reacts with dioxygen to decarboxylate the iron-coordinated benzilate. The oximate-bridged dinuclear complex (2), which contains a high-spin (TpPh2)FeII unit and a low-spin iron(II)–oximate unit, activates dioxygen at the high-spin iron(II) center. Both the complexes exhibit the oxidative transformation of oximes to the corresponding carbonyl compounds with the incorporation of one oxygen atom from dioxygen. In the oxidation process, the oxime units are converted to nitric oxide (NO) or nitroxyl (HNO). The iron(II)–benzilate complex (1) reacts with oximes to afford HNO, whereas the iron(II)–oximate complex (2) generates NO. The results described here suggest that the oxidative transformation of oximes to NO/HNO follows different pathways depending upon the nature of co-ligand/reductant.

Aliphatic C-H Bond Halogenation by Iron(II)-α-Keto Acid Complexes and O2: Functional Mimicking of Nonheme Iron Halogenases

α-Ketoglutarate-dependent nonheme halogenases catalyze the halogenation of aliphatic C-H bonds in the biosynthesis pathway of many natural products. An iron(IV)-oxo-halo species has been established as the active oxidant in the halogenation reactions. With an objective to emulate the function of the nonheme halogenases, two iron(II)-α-keto acid complexes, [(phdpa)Fe(BF)Cl] (1) and [(1,4-tpbd)Fe2(BF)2Cl2] (2) (where phdpa = N,N-bis(2-pyridylmethyl)aniline, 1,4-tpbd = N,N,N′,N'-tetrakis(2-pyridylmethyl)benzene-1,4-diamine, and BF = benzoylformate), have been prepared. The iron complexes are capable of carrying out the oxidative halogenation of aliphatic C-H bonds using O2 as the terminal oxidant. Although the complexes are not selective toward C-H bond halogenation, they are the only examples of nonheme iron(II)-α-keto acid complexes mimicking the activity of nonheme halogenases. The dinuclear complex (2) exhibits enhanced reactivity toward C-H bond halogenation/hydroxylation.

Silver(I)-Catalyzed Widely Applicable Aerobic 1,2-Diol Oxidative Cleavage

The oxidative cleavage of 1,2-diols is a fundamental organic transformation. The stoichiometric oxidants that are still predominantly used for such oxidative cleavage, such as H5IO6, Pb(OAc)4, and KMnO4, generate stoichiometric hazardous waste. Herein, we describe a widely applicable and highly selective silver(I)-catalyzed oxidative cleavage of 1,2-diols that consumes atmospheric oxygen as the sole oxidant, thus serving as a potentially greener alternative to the classical transformations.

1,4-Conjugate addition/esterification of: Ortho -quinone methides in a multicomponent reaction

A novel 1,4-conjugate addition/esterification of ortho-quinone methides in a multicomponent reaction has been developed. In this protocol, numerous carboxylic acids, ynamides and in situ generated ortho-quinone methides could assemble rapidly to constitut