Aromatic Ketoximes Research Articles

Rh(III)-Catalyzed C-H Allylation of Aromatic Ketoximes with Vinylaziridines.

The Rh(III)-catalyzed reaction of aromatic ketoximes with 2-vinylaziridines affords ortho-allylation products of the phenyl rings of aromatic ketoximes in moderate to excellent yields. The reaction requires 0.5 equiv of NaOAc as a base and occurs under mild conditions. The protocol exhibits ortho-monoallylation selectivity, wide scope of substrates, and good compatibility of functional groups.

Rh(III)‐Catalyzed Direct Amination of Aromatic Ketoximes Enabled by Potassium Acetate

A method to achieve rhodium(III)‐catalyzed, potassium acetate enabled intermolecular C–H amination of ketoximes using various benzenesulfonamide, especially 4‐nitrobenzenesulfonamide is reported. Various aryl ketoximes substituted with electron‐withdrawing functional groups were all well tolerated and produced the corresponding products in moderate to good yields. A preliminary mechanistic study revealed that potassium acetate is essential to realizing intermolecular amination.

Rhodium(III)-Catalyzed Diastereoselective Ring-Opening of 7-Azabenzonorbornadienes with Aromatic Ketoximes: Synthesis of Benzophenanthridine Derivatives.

A rhodium(III)-catalyzed redox-neutral ring-opening of 7-azabenzonorbornadienes with aromatic ketoximes giving 2-arylated hydronaphthylamines in a highly diastereoselective manner is described. Later, the 2-arylated hydronaphthylamines were converted into highly sensitive 13,14-dehydro benzophenanthridine derivatives by HCl hydrolysis. Further, 13,14-dehydro benzophenanthridines were aromatized into biologically important benzophenanthridine derivatives in the presence of DDQ. A possible reaction mechanism was proposed and supported by deuterium labeling studies and isolation of a rhodacycle intermediate.

ChemInform Abstract: One Pot Synthesis of Phenanthridines Using a Palladium‐Catalyzed Cyclization of Aromatic Ketoximes with Aryl Iodides via Beckmann Rearrangement.

The catalytic reaction of ketoximes with aryl iodides via a Beckmann rearrangement in the presence of a catalytic amount of Pd(OAc)2, Ag2O and ZnBr2 gave substituted phenanthridines in good to excellent yield. In the reaction, aromatic ketoximes converted first to acetanilides in the presence of ZnBr2/TFA via a Beckmann rearrangement followed by arylation in the presence of palladium complex. Furthermore, ortho-arylated acetanilides were converted to phenanthridine derivatives in the presence of a Hendrickson reagent.

ChemInform Abstract: Ruthenium‐Catalyzed Oxidant‐Free Allylation of Aromatic Ketoximes with Allylic Acetates at Room Temperature.

AbstractA highly regioselective ortho‐allylation using the ketoxime substituent as directing group is presented.

Ruthenium-Catalyzed ortho Alkenylation of Aromatics with Alkenes at Room Temperature with Hydrogen Evolution

A ruthenium-catalyzed oxidant-free highly regioselective ortho alkenylation of substituted aromatics such as aromatic amides, aromatic ketoximes, and anilides with alkenes in the presence of AgSbF6 and acetic acid in ClCH2CH2Cl at room temperature is described. The alkenylation reaction provides ortho alkenylated aromatics along with evolution of H2 gas. In the reaction, no oxidant was used, and the whole catalytic reaction has occurred without changing the oxidation state of the metal.

Ruthenium-Catalyzed Oxidant-Free Allylation of Aromatic Ketoximes with Allylic Acetates at Room Temperature.

Substituted aromatic ketoximes reacted efficiently with allylic acetates in the presence of {[RuCl2(p-cymene)]2} and AgSbF6 in 1,2-dichloroethane at ambient temperature, providing ortho-allyl aromatic ketoximes in a highly regioselective manner without an oxidant. In the reaction, the acetate group of allyl acetate acts as a base to activate the C-H bond of aromatics. Later, ortho-allyl aromatic ketoximes were converted into ortho-allyl aromatic ketones in the presence of HCl.

ChemInform Abstract: Nickel‐Catalyzed Cycloaddition of Aromatic (O‐Benzyl)ketoximes with Alkynes to Produce Isoquinoline and Isoquinoline N‐Oxide Derivatives.

AbstractAn imidamide bearing a NMe2‐group instead one of the aryls does not give the desired product.

Base-Free Method for Preparation ofO-Sulfonyl Aldoximes Starting from Aldoximes and Sulfonyl Chlorides

A series of O-sulfonyl oxime derivatives have been synthesized by the reaction of oximes with sulfonyl chlorides in the presence of silver oxide and potassium iodide. In the case of aromatic aldoximes and ketoximes, desired products were obtained in 56%~87% yields. But then no desired products were obtained when p-nitrobenzaldoxime, aliphatic aldoximes and α,β-unsaturated aldoximes were employed as substrates in the process. Keywords O-sulfonyl oximes; synthesis; oximes; sulfonyl chlorides; silver oxide

Nickel-catalyzed Cycloaddition of Aromatic (O-Benzyl)ketoximes with Alkynes to Produce Isoquinoline and Isoquinoline N-Oxide Derivatives

Abstract A nickel-catalyzed cycloaddition of aromatic (O-benzyl)ketoximes with alkynes to afford 3,4-disubstituted isoquinoline derivatives has been developed. The reaction involves oxidative addition of N–O bond of O-benzylketoxime to Ni(0) and subsequent intermolecular C–H bond activation via elimination of benzyl alcohol. It was also found that ketoximes participate in the nickel-catalyzed reaction with alkynes to furnish isoquinoline N-oxide derivatives.

Easy Access to Isoquinolines and Tetrahydroquinolines from Ketoximes and Alkynes via Rhodium-Catalyzed C−H Bond Activation

Described herein is a convenient and highly regioselective synthesis of substituted isoquinoline derivatives from various aromatic ketoximes and alkynes via a one-pot, rhodium-catalyzed C-H bond activation. In addition, tetrahydroquinoline derivatives are formed in good yields from 2-arylidene-1-cyclohexanone oximes possessing an exocyclic double bond and from tetrahydroxanthone oximes. A possible mechanism is proposed that involves chelation-assisted C-H activation via oxidative addition of Rh(I) to an ortho-C-H bond, insertion of the alkyne, reductive elimination, intramolecular electrocyclization, and aromatization. This mechanism is supported by isolation of the ortho-alkenylation products 7p and 7q. Also described herein is an example of an iridium-catalyzed activation of an sp(3) C-H bond.

ChemInform Abstract: Asymmetric Reductive Acylation of Aromatic Ketoximes by Enzyme‐Metal Cocatalysis.

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.

Asymmetric Reductive Acylation of Aromatic Ketoximes by Enzyme-Metal Cocatalysis

We have developed an efficient procedure for the asymmetric synthesis of chiral amides from ketoximes. This one-pot procedure employs two different types of catalysts, Pd nanocatalyst and lipase, for three consecutive transformations including hydrogenation, racemization, and acylation. Eight ketoximes have been efficiently transformed to the corresponding amides in good yields (83-92%) and high enantiomeric excesses (93-98%).

RuCl3 Catalyzed Facile Conversion of Arylalkyl Ketoximes to Amides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Photosensitized Oxidative Deprotection of Oximes to Their Corresponding Carbonyl Compounds by Platinum(II) Terpyridyl Acetylide Complex

Platinum(II) terpyridyl acetylide complex (1) photosensitizes the oxidation of aldoximes 2-4, aliphatic acyclic and cyclic ketoximes 5-7, and aromatic ketoximes 8-10 into their corresponding carbonyl compounds with good to excellent yields in acetonitrile solution. This deprotection of oximes proceeds via singlet oxygen ((1)O(2)) mechanism. The photosensitizer can be easily separated from the product and unreacted starting material by extraction with ethyl acetate and reused for photooxidation without loss of (1)O(2)-generation capacity.

Synthesis of 2,3,4,5-tetrasubstituted pyrroles from aromatic ketoximes using the TiCl4/Et3N reagent system

Aryl alkyl ketoximes react with the TiCl4/Et3N reagent to give 2,3,4,5-tetrasubstituted pyrroles in moderate to good yields (55–81%).

RuCl3 Catalyzed Facile Conversion of Arylalkyl Ketoximes to Amides

A variety of aromatic ketoximes undergo Beckmann rearrangement upon treatment with a catalytic amount of RuCl3 in refluxing acetonitrile to furnish the corresponding amides in excellent yield and high selectivity.

A Convenient Procedure for the Preparation of Oxime Chloroformates.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A Convenient Procedure for the Preparation of Oxime Chloroformates

Triphosgene is a convenient reagent for the preparation of O-(chloroformyl)oximes from aliphatic and aromatic ketoximes.

ChemInform Abstract: Steric and Electronic Effects on the Reduction of O-Silylated Aromatic Ketoximes with Borane.

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.