α-Functionalization Of Carbonyl Compounds Research Articles

Cooperative Triple Catalysis Enables Deaminative α-Indolmethylation of Carbonyl Compounds with Gramines.

α-Functionalization of carbonyl compounds is an important reaction in synthetic chemistry. However, the development of novel synthetic strategies to realize this reaction is challenging. This study describes the α-indolmethylation of carbonyl compounds using cooperative copper, amine, and hydrogen-bond catalysis. This reaction provides a novel and efficient strategy for developing indolmethylated carbonyl compounds by deaminative coupling of gramines.

Iodine(III)-Based Hypervalent Iodine Electrophiles in Organic Synthesis

Abstract: The chemistry of hypervalent iodine reagents is now developed as an important tool of synthetic organic chemistry. These reagents play a key role in replacing the toxic heavy metal reagent because of their mild reaction condition and environmentally friendly nature. Mainly, these reagents were known for oxidative properties, but the scope of these reagents is not limited to oxidation reactions. In the past two decades, they have been used as versatile electrophiles in various key organic transformations. Recently, the demand for these reagents has increased drastically for green chemistry, mainly due to their application in catalysis. Hypervalent iodine reagents have been successfully used to develop various oxidative transformations such as the oxidation of different organic species, α-functionalization of carbonyl compounds, cyclization reactions, C-H activation reactions, lactonization and oxidative rearrangements. Moreover, the use of these reagents is not limited to general organic reactions but is successfully used to develop several stereoselective transformations by using chiral hypervalent iodine reagents. This review article highlights various acyclic and cyclic reactions where the hypervalent iodine reagents have been used as electrophiles.

Hypervalent Iodine Reagents in the Synthesis of Flavonoids and Related Compounds

Hypervalent iodine compounds have proved to be very useful reagents to bring about various oxidative transformations including (i) α-functionalization of carbonyl compounds, (ii) oxidation of phenols, and (iii) oxidative rearrangement of ketones and α,β- unsaturated ketones. These reactions find interesting applications in the development of newer and convenient approaches for the synthesis of flavonoids. This review focuses on the use of most common three hypervalent compounds, namely iodobenzene diacetate, [hydroxy(tosyloxy)iodo]benzene, and [bis-trifluoroacetoxy(iodo)]benzene in the synthesis of cis/trans-3-hydroxyflavanones, 3-hydroxyflavones (flavonols), flavones, isoflavones and related compounds.

Transition Metal-Catalyzed α-Position Carbon–Carbon Bond Formations of Carbonyl Derivatives

α-Functionalization of carbonyl compounds in organic synthesis has traditionally been accomplished via classical enolate chemistry. As α-functionalized carbonyl moieties are ubiquitous in biologically and pharmaceutically valuable molecules, catalytic α-alkylations have been extensively studied, yielding a plethora of practical and efficient methodologies. Moreover, stereoselective carbon–carbon bond formation at the α-position of achiral carbonyl compounds has been achieved by using various transition metal–chiral ligand complexes. This review describes recent advances—in the last 20 years and especially focusing on the last 10 years—in transition metal-catalyzed α-alkylations of carbonyl compounds, such as aldehydes, ketones, imines, esters, and amides and in efficient carbon–carbon bond formations. Active catalytic species and ligand design are discussed, and mechanistic insights are presented. In addition, recently developed photo-redox catalytic systems for α-alkylations are described as a versatile synthetic tool for the synthesis of chiral carbonyl-bearing molecules.

Stereodivergent Catalysis.

This review covers diastereo- and enantiodivergent catalyzed reactions in acyclic and cyclic systems using metal complexes or organocatalysts. Among them, nucleophilic addition to carbon-carbon and carbon-nitrogen double bonds, α-functionalization of carbonyl compounds, allylic substitutions, and ring opening of oxiranes and aziridines are considered. The diastereodivergent synthesis of alkenes from alkynes is also included. Finally, stereodivergent intramolecular and intermolecular cycloadditions and other cyclizations are also reported.

ChemInform Abstract: Reagent and Catalyst Design for Asymmetric Hypervalent Iodine Oxidations

AbstractReview: [87 refs.

Reagent and Catalyst Design for Asymmetric Hypervalent Iodine Oxidations

In this review are compiled the different possible transformations using environmentally benign chiral hypervalent iodine reagents and catalysts. Herein is presented an overview of asymmetric oxidation of sulfides to sulfoxides, oxidation of alkenes, α-functionalization of carbonyl compounds and dearomatization reactions. 1 Introduction 2 Chiral Hypervalent Iodine Reagents 3 Oxidation of Sulfides to Sulfoxides 4 Oxidation of Alkenes 5 α-Functionalization of Carbonyl Compounds 6 Dearomatization Reactions 7 Conclusion

α-Functionalization of Carbonyl Compounds Using Hypervalent Iodine Reagents

α-Functionalized carbonyl compounds are versatile intermediates in organic synthesis. A broad range of both carbon and heteroatom substituents can be introduced into the α-position of carbonyl compounds using hypervalent iodine reagents. Herein we summarize the use of these environmentally benign reagents with particular emphasis on catalytic and asymmetric methodology developed over the past decade.

Hypervalent iodine in organic synthesis: α-functionalization of carbonyl compounds

Hypervalent iodine in organic synthesis: α-functionalization of carbonyl compounds