Ketone Oxime Research Articles

A new linear trinuclear cobalt complex bearing oximato and azido ligands: synthesis, structure, and magnetic characterization

The reaction of CoCl2 · 6H2O, mpkoH (methyl 2-pyridyl ketone oxime), NEt3, and NaN3 in a 1 : 1 : 2 : 1 molar ratio affords a linear trinuclear complex, [CoII(mpko)4(N3)4(H2O)2] (1). Complex 1 has been characterized by single-crystal X-ray diffraction, elemental analysis, and infrared spectrum. Three cobalt ions are in the center of distorted octahedra, which are connected by two μ-1,1 azides and two oxime oxygen atoms to form a linear trinuclear structure. Discrete units of 1 are connected to form a stable 3-D supramolecular network by C–H···O and C–H···N weak interactions. Variable temperature magnetic susceptibility measurements reveal that 1 exhibits antiferromagnetic behavior.

Synthesis of Isoquinolines and Heterocycle-Fused Pyridines via Three-Component Cascade Reaction of Aryl Ketones, Hydroxylamine, and Alkynes

An efficient one-pot synthesis of isoquinolines and heterocycle-fused pyridines by three-component reaction of aryl ketones, hydroxylamine, and alkynes is developed. The reaction involves condensation of aryl ketones and hydroxylamine, rhodium(III)-catalyzed C-H bond activation of the in situ generated aryl ketone oximes, and cyclization with internal alkynes. This protocol enables rapid assembly of multisubstituted isoquinolines as well as γ-carbolines, furo[2,3-c]pyridines, thieno[2,3-c]pyridines, and benzofuro[2,3-c]pyridines from readily available substrates.

Employment of methyl 2-pyridyl ketone oxime in 3d/4f-metal chemistry: dinuclear nickel(ii)/lanthanide(iii) species and complexes containing the metals in separate ions

The use of methyl 2-pyridyl ketone oxime (mpkoH) for the synthesis of Ni(II)/Ln(III) (Ln = lanthanide) complexes, using "one-pot" reactions in the absence of an external base, is described. Depending on the reaction and crystallization conditions employed, two families of complexes have been obtained. The first family consists of true heterometallic species and involves complexes [NiLn(mpko)(3)(mpkoH)(3)](ClO(4))(2), where Ln = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er. The second family contains the pseudo heterometallic complexes [Ni(mpkoH)(3)](2)[Ln(NO(3))(6)](ClO(4)), where Ln = La, Ce, Pr, Nd and Sm. The crystal structures of [NiCe(mpko)(3)(mpkoH)(3)](ClO(4))(2) (1), [NiDy(mpko)(3)(mpkoH)(3)](ClO(4))(2) (8) and [Ni(mpkoH)(3)](2)[La(NO(3))(6)](ClO(4)) (11) have been determined by single-crystal, X-ray crystallography. Complexes 1·1.2MeOH·0.6H(2)O and 8·1.2MeOH·0.6H(2)O crystallise in the monoclinic space group P2(1)/a and are isomorphous; there are two crystallographically independent cations in the unit cell, but their interatomic distances and angles differ little. The Ni(II) and Ln(III) ions are bridged by three oximate groups belonging to the η(1):η(1):η(1):μ mpko(-) ligands. The Ni(II) centre is octahedrally coordinated by the six nitrogen atoms of the mpko(-) ligands in a facial arrangement. The Ln(III) centre is bound to an (O(oximate))(3)N(6) set of donor atoms, the nitrogen atoms belonging to the three N,N'-bidentate chelating mpkoH ligands. The stereochemistry of the Ln(III) atoms has been evaluated by means of continuous shape measures (CShM). The two crystallographically independent Ce(III) atoms in 1 have tricapped trigonal prismatic and capped square antiprismatic coordination geometries, while the polyhedra of the Dy(III) atoms in 8 are both close to a tricapped trigonal prism. The octahedral Ni(II) atoms in 11 are both facially bound to a N(6) set of donor atoms from three N,N'-bidentate chelating mpkoH ligands, while the 12-coordinate La(III) centre in [La(NO(3))(6)](3-) is coordinated by six bidentate chelating nitrato groups. Variable-temperature, solid state dc magnetic susceptibility studies were carried out on complexes 2, 6, 7 and 8. The dc susceptibility data for 6 in the 2.0-300 K range have been fit to a model with one J value, revealing an antiferromagnetic Ni(II)···Gd(III) exchange interaction [J = -1.1 cm(-1) based on H = -J (Ŝ(Ni)·Ŝ(Gd))]. Antiferromagnetic Ni(II)···Pr(III), Ni(II)···Tb(III) and Ni(II)···Dy(III) exchange interactions have also been suggested for 2, 7 and 8, respectively. The combined work demonstrates the usefulness of mpko(-) in the preparation of interesting Ni(II)/Ln(III) compounds, without requiring the presence of external base and ancillary organic ligands.

Acid hydrolysis of amides obtained by Beckmann rearrangement of methyl ketones oximes of unsaturated γ-lactone, aromatic, and alicyclic series

Beckmann rearrangement was performed of oximes of substituted 3-acetyl-4-methyl-5,5-dimethyl(pentamethylene)-2-oxo-2,5-dihydrofuranes in the presence of boron trifluoride etherate. Aiming at establishing the spatial arrangement of the oximes the hydrolysis was carried out of acid amides obtained by Beckmann rearrangement of oximes of methyl ketones belonging to unsaturated γ-lactone series and also to aromatic and alicyclic series. The hydrolysis with 20% sulfuric acid led to the formation of the corresponding acid and amine, and the hydrolysis with acetic and hydrochloric acids resulted in retrobeckmann rearrangement giving the initial oximes.

Synthesis and Structural Characterization of a New Tetranuclear Nickel(II) Sulfato Complex Containing the Anionic Form of Di-2-Pyridyl Ketone Oxime

The preparation and crystal structure of a tetranuclear Ni(II) sulfato cluster containing the anion of di-2-pyridyl ketone oxime, (py)2CNO−, are reported. Treatment of NiSO4·6H2O with one equivalent of (py)2CNOH and one equivalent of NEt3 in MeOH leads to the compound [Ni4{(py)2CNO}4(SO4)2(MeOH)4] (1) in moderate yield. The metal ions are linked together by two 3.2111 and two 2.1110 (Harris notation) (py)2CNO− ligands, as well as two 2.1100 SO42− ions to create a rare metallacrown-type (12-MC-4) ring. Strong H-bond intermolecular interactions in 1 lead to the formation of a 1D chain along the axis. Characteristic IR bands are discussed in terms of the known structure of 1.

Reactions of 2′-oxo-1′,2′-dihydrospiro[cyclopropane-1,3′-indole]-2,2,3,3-tetracarbonitriles with nucleophiles

2′-Oxo-1′,2′-dihydrospiro[cyclopropane-1,3′-indole]-2,2,3,3-tetracarbonitriles reacted with oxygencentered nucleophiles to form addition products at the cyano groups with conservation of the three-membered ring. Reactions of the title compounds with alcohols required the presence of base catalyst, and the products, 2-amino-4,4-dialkoxy-2′-oxo-1′,2′-dihydrospiro[3-azabicyclo[3.1.0]hex-2-ene-6,3′-indole]-1,5-dicarbonitriles, were converted into the corresponding 2-imino-2′,4-dioxospiro[3-azabicyclo[3.1.0]hexane-6,3′-indole]-1,5-dicarbonitriles and 2,2′,4-trioxospiro[3-azabicyclo[3.1.0]hexane-6,3′-indole]-1,5-dicarbonitriles by the action of acetic and sulfuric acids, respectively. The reactions with ketone oximes occurred in the absence of a catalyst, yielding 2-amino-4,4-bis(alkylideneaminooxy)-2′-oxo-1′,2′-dihydrospiro[3-azabicyclo[3.1.0]hex-2-ene-6,3′-indole]-1,5-dicarbonitriles. The reactions with thiols, aliphatic amines, and anilines were accompanied by opening of the three-membered ring. In the reactions with triphenylphosphine and thiols 2-(2-oxo-2,3-dihydro-1H-indol-3-ylidene)malononitrile was obtained, while morpholine and N,N-dimethylaniline gave rise, respectively, to 3,3-diaryl-and 3,3-dimorpholino-1H-indol-2(3H)-ones and tri- and dicyanoethylene derivatives.

Combining Azide, Carboxylate, and 2-Pyridyloximate Ligands in Transition-Metal Chemistry: Ferromagnetic NiII5 Clusters with a Bowtie Skeleton

The combined use of the anion of phenyl(2-pyridyl)ketone oxime (ppko(-)) and azides (N(3)(-)) in nickel(II) carboxylate chemistry has afforded two new Ni(II)(5) clusters, [Ni(5)(O(2)CR')(2)(N(3))(4)(ppko)(4)(MeOH)(4)] [R' = H (1), Me (2)]. The structurally unprecedented {Ni(5)(μ-N(3))(2)(μ(3)-N(3))(2)}(6+) cores of the two clusters are almost identical and contain the five Ni(II) atoms in a bowtie topology. Two N(3)(-) ions are end-on doubly bridging and the other two ions end-on triply bridging. The end-on μ(3)-N(3)(-) groups link the central Ni(II) atoms with the two peripheral metal ions on either side of the molecule, while the Ni···Ni bases of the triangles are each bridged by one end-on μ-N(3)(-) group. Variable-temperature, solid-state direct- (dc) and alternating-current (ac) magnetic susceptibility, and magnetization studies at 2.0 K were carried out on both complexes. The data indicate an overall ferromagnetic behavior and an S = 5 ground state for both compounds. The ac susceptibility studies on 1 reveal nonzero, frequency-dependent out-of-phase (χ(M)") signals at temperatures below ~3.5 K; complex 2 reveals no χ(M)" signals. However, single-crystal magnetization versus dc field scans at variable temperatures and variable sweep rates down to 0.04 K on 1 reveal no noticeable hysteresis loops, except very minor ones at 0.04 K assignable to weak intermolecular interactions propagated by nonclassical hydrogen bonds.

Formation of N-benzylbenzamide from benzyl phenyl ketone oxime in a system C2H2-KOH-DMSO. Key role of acetylene

Oximes rearrange into amides under the action of strong acids (Beckmann rearrangement) [1]. Only seldom this rearrangement occurs in the presence of bases, for instance, that of benzoquinosylidone Eand Z-oximes [2]. The preparation of benzamide from benzaldoxime in the system KOH–DMSO was described through hydration of the intermediate nitrile [3]. In the course of the synthesis of 1-vinyl-2,3-diphenylpyrrole (II) from benzyl phenyl ketone oxime (I) and acetylene by Trofi mov reaction [4–6] in the system KOH–DMSO at the atmospheric pressure (130°C, 7 h) alongside the expected pyrrole II (yield 14–34%) N-benzylbenzamide (III) was obtained (14–24%) (Scheme1). Besides after acidifying the reaction mixture benzoic acid was isolated (up to 56%). Special experiment showed that amide III was not a product of oxime I rearrangement under the action of KOH–DMSO (at heating oxime I under the same conditions without acetylene it was nearly completely recovered, to 95–97%). Obviously the key role in the formation of amide III from oxime I belonged to acetylene. Apparently O-vinyloxime IV, the intermediate in the synthesis of pyrroles from oximes and acetylene, was deprotonated by the superbase KOH–DMSO forming carbanion V that further replaced intramolecularly the vinyloxy anion with the closure of the azirine ring VI (Scheme 2). Its hydration into hydroxyaziridine VII followed by a rearrangement resulted in amide III. The stage of azirine formation from O-vinyloxime under the action of the superbase was suggested recently for the understanding of the assembling of 4-methylene-3oxa-1-azabicyclo[3.1.0]hexanes from ketoximes, ketones, and acetylene [7]. In essence this stage resembles the azirine synthesis from oximes or their ethers by Hoch– Campbell reaction [1, 8]. This reaction fundamentally supplements the common Scheme 1. Dedicated to Full Member of the Russian Academy of Sciences N.S. Zefi rov on occasion of his 75th anniversary

ChemInform Abstract: Trifluoromethyl Ketone Oximes and Allylic Grignard Reagents: A Synthetic Route to Homoallylic Hydroxylamines and Homoallylic Primary Amines.

The reaction between Grignard reagents and oximes derived from trifluoromethyl ketones has been studied

ChemInform Abstract: Photoinduced Molecular Transformations. Part 133. New Photoinduced Deconjugation of Steroidal α,β-Unsaturated Cyclic Ketone Oxime into the β,γ-Unsaturated Isomer Involving Stereospecific Proton Transfer.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: 1,3,5‐Triphenylbenzene as Unexpected By‐Product in the Synthesis of 2,5‐Diphenylpyrrole from Acetophenone Oxime and Phenylacetylene.

Despite poor yield of the target product (25%), the reaction of acetophenone oxime (I) with phenylacetylene (II) in superbasic medium (Trofimov reaction) [1–4], leading to 2,5-diphenyl-1H-pyrrole (III), attracts interest from the preparative viewpoint, for alternative methods include a number of steps [5], and the overall yield (calculated with account taken of all steps) is comparable to that in the Trofimov synthesis. Determination of structure of by-products in the reaction of oxime I with acetylene II may be useful for understanding its mechanism and further optimization to enhance its preparative efficiency. We were the first to isolate from the product mixture (LiOH–DMSO, 130°C, 5 h) 6% of 1,3,5-triphenylbenzene (V) together with pyrrole III and acetophenone IV (deoximation product of initial oxime I) (Scheme 1). However, this assumption was not confirmed experimentally. We also found that under the given conditions compound V cannot be formed as a result of autocondensation of oxime I or ketone IV. Presumably, O-vinyl oxime VI which is the primary intermediate in the synthesis of pyrroles from ketone oximes and acetylene [6] (Scheme 2) undergoes rearrangement into nitrone VII (as reported in [7] for cyclohexanone oxime O-allyl ether). Enhanced CH acidity of the CH3 group in VII due to strong electron-withdrawing effect of the N-oxide fragment favors aldolization (crotonization) of VII with acetophenone IV. The condensation of azatriene VIII thus formed with the second acetophenone molecule gives azatetraene IX, and cyclization of the latter, followed by aromatization of dihydrobenzene X via elimination of vinylnitrone XI, yields triphenylbenzene V. Compound XI can be converted into acetophenone oxime (I).

ChemInform Abstract: Synthesis of Azabicyclic Compounds from Terpene Ketone Oximes of Bicyclo(2.2.1)heptane Series.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Pd-Catalyzed Ortho-C−H Acylation/Cross Coupling of Aryl Ketone O-Methyl Oximes with Aldehydes Using tert-Butyl Hydroperoxide as Oxidant

A Pd-catalyzed protocol for direct C-H bond acylation by cross coupling of aryl ketone oximes and aldehydes using tert-butyl hydroperoxide (TBHP) as oxidant was developed. With oximes as a directing group for the C-H activation, the coupling with aldehydes was achieved with remarkable regioselectivity. The acylation reactions exhibit excellent functional group tolerance, and both aliphatic and heteroaromatic aldehydes can be effectively coupled to the oximes.

Microwave Promoted Regeneration of Carbonyl Compounds from Oximes Using N, N‐Dichloro Poly(Styrene‐co‐divinylbenzene)Sulphonamide Resin

An efficient, economically viable and operationally simple method was developed for deoximation of oximes (of ketones and aldehydes) to their corresponding carbonyl compounds using polymer beads of N, N‐dichloro poly(styrene‐co‐divinylbenzene)sulphonamide resin. Polymeric reagent offered speedy conversion and substantial yields of products under mild condition and is recyclable. Deoximation was monitored by the use of 13C NMR.

New Mixed‐Valence MnII/III6 Complexes Bearing Oximato and Azido Ligands: Synthesis, and Structural and Magnetic Characterization

AbstractThe combined use of the anion of methyl 2‐pyridyl ketone oxime (mpko–) and azides (N3–) in non‐carboxylate Mn chemistry has afforded two new Mn6 clusters, [Mn6O3(N3)3(mpko)6(H2O)3](ClO4)2 (1) and [Mn6O3(N3)5(mpko)6(H2O)] (2), which are mixed‐valence (MnII, 5 MnIII). The 1:1:1:1 reaction of Mn(ClO4)2·6H2O, mpkoH, NaN3 and NEt3 in MeOH gave the cationic complex 1, while a similar reaction using additional NaO2CMe led instead to the neutral complex 2. The structurally unprecedented cores of the two cages are very similar, and contain the six Mn ions in a topology comprising three vertex‐sharing oxide‐centered triangles bridged by two end‐on azides. Variable‐temperature, solid‐state dc and ac magnetization studies were carried out for 1 and 2 in the 1.8–300 K range. The data reveal S = 5/2 ground states for both complexes, and fitting of magnetization vs. field (H) and temperature (T) data by matrix diagonalization for 1 gave S = 5/2, D = –1.4(3) cm–1, and g = 1.99(1), where D is the axial zero‐field splitting (ZFS) parameter. The combined results demonstrate the versatility of 2‐pyridyl ketone oxime anions in the presence of suitable ancillary ligands, such as azides, for the synthesis of new Mn clusters, without requiring the co‐presence of carboxylate ligands.

Rare Oxidation-State Combinations and Unusual Structural Motifs in Hexanuclear Mn Complexes Using 2-Pyridyloximate Ligands

The use of phenyl-2-pyridyl ketone oxime and di-2-pyridyl ketone oxime in Mn chemistry has led to hexanuclear clusters with unprecedented (Mn(II)(4)Mn(III)Mn(IV)) or extremely rare (Mn(II)Mn(III)(5) and Mn(II)(3)Mn(III)(3)) metal oxidation-state combinations and uncommon structural motifs.

Reaction Behavior for Synthesis of Methyl Ethyl Ketone Oxime Catalyzed by Titanosilicate/H<SUB>2</SUB>O<SUB>2</SUB> Systems

Reaction Behavior for Synthesis of Methyl Ethyl Ketone Oxime Catalyzed by Titanosilicate/H<SUB>2</SUB>O<SUB>2</SUB> Systems

1,3,5-triphenylbenzene as unexpected by-product in the synthesis of 2,5-diphenylpyrrole from acetophenone oxime and phenylacetylene

Despite poor yield of the target product (25%), the reaction of acetophenone oxime (I) with phenylacetylene (II) in superbasic medium (Trofimov reaction) [1–4], leading to 2,5-diphenyl-1H-pyrrole (III), attracts interest from the preparative viewpoint, for alternative methods include a number of steps [5], and the overall yield (calculated with account taken of all steps) is comparable to that in the Trofimov synthesis. Determination of structure of by-products in the reaction of oxime I with acetylene II may be useful for understanding its mechanism and further optimization to enhance its preparative efficiency. We were the first to isolate from the product mixture (LiOH–DMSO, 130°C, 5 h) 6% of 1,3,5-triphenylbenzene (V) together with pyrrole III and acetophenone IV (deoximation product of initial oxime I) (Scheme 1). However, this assumption was not confirmed experimentally. We also found that under the given conditions compound V cannot be formed as a result of autocondensation of oxime I or ketone IV. Presumably, O-vinyl oxime VI which is the primary intermediate in the synthesis of pyrroles from ketone oximes and acetylene [6] (Scheme 2) undergoes rearrangement into nitrone VII (as reported in [7] for cyclohexanone oxime O-allyl ether). Enhanced CH acidity of the CH3 group in VII due to strong electron-withdrawing effect of the N-oxide fragment favors aldolization (crotonization) of VII with acetophenone IV. The condensation of azatriene VIII thus formed with the second acetophenone molecule gives azatetraene IX, and cyclization of the latter, followed by aromatization of dihydrobenzene X via elimination of vinylnitrone XI, yields triphenylbenzene V. Compound XI can be converted into acetophenone oxime (I).

Mononuclear and Dinuclear Manganese(II) Complexes from the Use of Methyl(2‐pyridyl)ketone Oxime

The reactions of methyl(2-pyridyl)ketone oxime, (py)C(Me)NOH, with manganese(II) sulfate monohydrate have been investigated. The reaction between equimolar quantities of MnSO4 · H2O and (py)C(Me)NOH in H2O lead to the dinuclear complex [Mn2(SO4)2{(py)C(Me)NOH}4] · (py)C(Me)NOH, 1 · (py)C(Me)NOH, while employment of NaOMe as base affords the compound [Mn(HCO2)2{(py)C(Me)NOH}2] (2). The structures of both compounds have been determined by single crystal X-ray diffraction. In both complexes, the organic ligand chelates through its nitrogen atoms. The IR data are discussed in terms of the nature of bonding and the structures of the two complexes.

ChemInform Abstract: Synthesis of Alkyl Nitrones by Reaction of Aldehyde and Ketone Oximes with α,β‐Unsaturated Esters in the Presence of Lewis Acid.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.