Oxidative Difunctionalization Research Articles

ChemInform Abstract: Iodine(III)‐Mediated Diazidation and Azido‐Oxyamination of Enamides.

AbstractThe in‐situ‐umpolung of halide salts for oxidative difunctionalization of enamides is extended to lithium azide to provide diastereoselective diazidation of N‐substituted allylamines.

Reagent-switch controlled metal-free intermolecular geminal diamination and aminooxygenation of vinylarenes

We report here the first general method for the geminal diamination and an intermolecular metal-free, geminal aminooxygenation of vinylarenes using hypervalent iodine reagent. A new m-CPBA mediated geminal aminooxygenation is also reported. A novel reagent-switch for the control of migrating group by controlling the two independent geminal addition paths is developed. Deuterium labelling studies and the control studies have provided unambiguous evidences for the phenyl migration and hydride migration in the oxidative geminal difunctionalization process mediated by PhI(OCOCF3)2 and m-CPBA, respectively through a semi-pinacol rearrangement.

Direct difunctionalization of activated alkynes via domino oxidative benzylation/1,4-aryl migration/decarboxylation reactions under metal-free conditions.

The oxidative difunctionalization of aryl alkynoates via benzyl radical initiated intramolecular 1,4-aryl migration and decarboxylation tandem process was developed in the presence of tert-butyl hydroperoxide as an oxidant, which provides a direct and selective route to a variety of trisubstituted alkenes from simple toluene derivatives and aryl alkynoates.

Oxidative difunctionalization of alkynoates via cascade radical addition, aryl migration, and decarboxylation

A cascade radical oxidative difunctionalization of alkynoates with simple ethers for the construction of tri-substituted olefins is developed. The reaction undergoes cascade radical addition to C–C triple bond, 1,4-aryl migration, and decarboxylation to deliver a variety of difunctionalized alkenes in moderate to good yields. This procedure also represents a promising strategy for the direct functionalization of the α-Csp3-H bonds in ether derivatives.

Oxidative Difunctionalization of Alkynoates through Alkylation and Migration Decarboxylative Arylation.

A cascade oxidative difunctionalization reaction of alkynoates for the construction of trisubstituted olefins has been developed. The process undergoes alkylation of a C-C triple bond, 1,4-aryl migration, and decarboxylation, which demonstrates a multistep radical cascade reaction for the difunctionalization of alkynoates and also represents a strategy of direct decarboxylation of esters.

ChemInform Abstract: Enamide Derivatives: Versatile Building Blocks for Total Synthesis

AbstractReview: [100 refs.

ChemInform Abstract: Palladium‐Catalyzed Oxidative Heck‐Type Alkylation/Aryl Migration/Desulfonylation Between Alkenes with α‐Carbonyl Alkyl Bromides.

A new Pd(II)-catalyzed alkene oxidative difunctionalization initiated by Heck insertion has been developed for the selective synthesis of acyclic and cyclic all-carbon quaternary stereocenters, which achieves an oxidative Heck-type alkylation, aryl migration, and desulfonylation sequence and represents a different input from those previously used Heck coupling in synthesis is reported.

Enamide Derivatives: Versatile Building Blocks for Total Synthesis

Enamides and enecarbamates are versatile building blocks in organic synthesis. This review describes the development of enamide chemistry and the utility of the resulting products in the synthesis of a variety of important, biologically active molecules. 1 Introduction 2 Asymmetric Hydrogenation of Enamides 3 Monofunctionalization of Enamide Derivatives 3.1 Palladium-Catalyzed α-Functionalization of Enamide Derivatives 3.2 Ruthenium-Catalyzed β-Functionalization of Enamide Derivatives 4 Ionic Vicinal Difunctionalization of Enamide Derivatives 4.1 Tandem Difunctionalization of Enamide Derivatives 4.2 Cycloadditions 4.2.1 [4+2] Cycloadditions 4.2.2 [2+2] Cycloadditions 4.2.3 Cyclopropanation of Enamides 4.3 Other Pericyclic Reactions 4.3.1 Electrocyclization Reactions 4.3.2 Overman Rearrangement 4.4 Platinum-Catalyzed Vicinal Difunctionalization of Enamide Derivatives 5 Radical Vicinal Difunctionalization of Enamide Derivatives 6 Oxidative Vicinal Difunctionalization of Enamide Derivatives 7 N-Arylation of Enecarbamates 8 Conclusion 9 Ligand Glossary

Nitrative Spirocyclization Mediated by TEMPO: Synthesis of Nitrated Spirocycles from N‐Arylpropiolamides, tert‐Butyl Nitrite and Water

AbstractA new method for the nitrative spirocyclization of alkynes is described. This method involves the oxidative difunctionalization of alkynes initiated by a radical attack pathway using t‐BuONO (tert‐butyl nitrite) combined with water as the nitro source and TEMPO [(2,2,6,6‐tetramethyl‐piperidin‐1‐yl)oxyl] as the initiator, and it represents a new example of oxidative alkyne difunctionalization via the formation of CN/CC bonds for the assembly of nitroalkene unit‐containing spirocycles.magnified image

Palladium-Catalyzed Oxidative Heck-Type Alkylation/Aryl Migration/Desulfonylation between Alkenes with α-Carbonyl Alkyl Bromides

A new Pd(II)-catalyzed alkene oxidative difunctionalization initiated by Heck insertion has been developed for the selective synthesis of acyclic and cyclic all-carbon quaternary stereocenters, which achieves an oxidative Heck-type alkylation, aryl migration, and desulfonylation sequence and represents a different input from those previously used Heck coupling in synthesis is reported.

ChemInform Abstract: Palladium‐Catalyzed Oxidative Difunctionalization of Alkenes with α‐Carbonyl Alkyl Bromides Initiated Through a Heck‐Type Insertion: A Route to Indolin‐2‐ones.

AbstractA new palladium‐catalyzed oxidative difunctionalization reaction of N‐arylalkenes with primary, secondary, and tertiary α‐carbonyl alkyl bromides affording indolinones is presented.

ChemInform Abstract: “One‐Pot” Access to Dihydrofurans via Tandem Oxidative Difunctionalization and Ring Contraction of Aminopyrans.

AbstractThe sequential addition of NCS and a base to 2‐amino‐4H‐pyran derivatives (I) and (IV) in alcohol medium affords dihydrofurans (III) and (V), resp., in good yields.

ChemInform Abstract: Iron‐Catalyzed Oxidative Arylmethylation of Activated Alkenes Using a Peroxide as the Methyl Source.

A novel, simple route for the synthesis of oxindoles is presented via iron-catalyzed oxidative arylmethylation of activated alkenes with peroxides. This work is realized by the use of a peroxide as the methyl source and 1,4-diazabicyclo[2.2.2]octane as the ligand and represents a new access to oxindoles through an alkene oxidative difunctionalization process.

Palladium‐Catalyzed Oxidative Difunctionalization of Alkenes with α‐Carbonyl Alkyl Bromides Initiated through a Heck‐type Insertion: A Route to Indolin‐2‐ones

AbstractThe oxidative interception of various σ‐alkyl palladium(II) intermediates with additional reagents for the difunctionalization of alkenes is an important research area. A new palladium‐catalyzed oxidative difunctionalization reaction of alkenes with α‐carbonyl alkyl bromides is described, in which the σ‐alkyl palladium(II) intermediate is generated through a Heck insertion and trapped using an aryl C(sp2)H bond. This method can be applied to various α‐carbonyl alkyl bromides, including primary, secondary, and tertiary α‐bromoalkyl esters, ketones, and amides.

Palladium-catalyzed oxidative difunctionalization of alkenes with α-carbonyl alkyl bromides initiated through a Heck-type insertion: a route to indolin-2-ones.

The oxidative interception of various σ-alkyl palladium(II) intermediates with additional reagents for the difunctionalization of alkenes is an important research area. A new palladium-catalyzed oxidative difunctionalization reaction of alkenes with α-carbonyl alkyl bromides is described, in which the σ-alkyl palladium(II) intermediate is generated through a Heck insertion and trapped using an aryl C(sp(2))-H bond. This method can be applied to various α-carbonyl alkyl bromides, including primary, secondary, and tertiary α-bromoalkyl esters, ketones, and amides.

Iron-Catalyzed Oxidative Arylmethylation of Activated Alkenes Using a Peroxide as the Methyl Source

A novel, simple route for the synthesis of oxindoles is presented via iron-catalyzed oxidative arylmethylation of activated alkenes with peroxides. This work is realized by the use of a peroxide as the methyl source and 1,4-diazabicyclo[2.2.2]octane as the ligand and represents a new access to oxindoles through an alkene oxidative difunctionalization process.

"One-pot" access to dihydrofurans via tandem oxidative difunctionalization and ring contraction of aminopyrans.

An operationally simple and efficient protocol for the construction of dihydrofuran derivatives has been accomplished via a sequential addition of N-chlorosuccinimide and a base to 2-amino-4H-pyran derivatives in alcohol medium. The one-pot protocol proceeding via tandem oxidative difunctionalization and ring contraction provides an entirely new strategy for the construction of the dihydrofuran skeleton.

ChemInform Abstract: Oxidative Difunctionalization of 2‐Amino‐4H‐pyrans in Iodobenzene Diacetate and N‐Chlorosuccinimide: Reactivity, Mechanistic Insights, and DFT Calculations.

AbstractIn the presence of PhI(O‐Ac)2 and simple alcohols, 2‐aminopyrans undergo unusual geminal dialkoxylation with 1,2‐migration of the amino group.

Stereo- and regioselectivity in the P450-catalyzed oxidative tandem difunctionalization of 1-methylcyclohexene

The selective partial oxidation of small non-functionalized molecules using biocatalysis based on P450 monooxygenases is known to be difficult due to the expected poor regio- and stereoselectivity, but in this study it was nevertheless attempted. 1-Methylcyclohexene was subjected to oxygen-mediated biocatalytic oxidation using P450-BM3 as the catalyst. Both oxidative hydroxylation and epoxidation were observed, in some cases leading to hydroxy epoxides with high diastereo- and enantioselectivity especially when employing BM3 mutants.

Pd(II)-Catalyzed Sequential C–C/C–O Bond Formations: A New Strategy to Construct Trisubstituted Furans

Palladium-catalyzed oxidative difunctionalization of enol ethers with 1,3-dicarbonyl compounds to construct trisubstituted furans in one step under mild conditions is described. The reaction is thought to proceed through a C-C bond formation along with a C-O bond closing the ring structure. Oxygen is the sole oxidant regenerating the Pd(II) catalyst.