Chemical Chameleons Research Articles

Desulfonylative Functionalization of Organosulfones via Inert (Hetero)Aryl C(sp2)-SO2 Bond Cleavage.

As "chemical chameleons," organosulfones have been widely applied in various desulfonylative functionalization reactions. However, the desulfonylative functionalization of (hetero)arylsulfones through the cleavage of inert C(sp2)-SO2 bonds remains a challenging and underexplored task. Over the past twenty years, the use of (hetero)arylsulfones as arylation reagents has gradually gained attention in diverse cross-coupling reactions under specific catalytic conditions, especially in transition metal-catalysis and photocatalysis chemistry. In this review, we discuss the representative accomplishments and mechanistic insights achieved in desulfonylative reactions of inactive C(sp2)-SO2 bonds in (hetero)arylsulfones, including: (i) transition-metal-catalyzed desulfonylative cross-coupling reactions and (ii) photo-/electrocatalytic radical desulfonylative coupling reactions. We anticipate that this review will provide an overall perspective in this area to a general audience of researchers and stimulate further innovative strategies for desulfonylative functionalization of inert arylsulfones.

N-Heteroaromatic Fluoroalkylation through Ligand Coupling Reaction of Sulfones.

Ligand coupling on hypervalent main group elements has emerged as a pivotal methodology for the synthesis of functionalized N-heteroaromatic compounds in recent years due to the avoidance of transition metals and the mildness of the reaction conditions. In this direction, the reaction of N-heteroaryl sulfur(IV) and N-heteroaryl phosphorus(V) compounds has been well studied. However, the ligand coupling of sulfur(VI) is still underdeveloped and the reaction of alkyl N-heteroarylsulfones is still elusive, which does not match the high status of sulfones as the chemical chameleons in organic synthesis. Here we present a ligand coupling-enabled formal SO2 extrusion of fluoroalkyl 2-azaheteroarylsulfones under the promotion of Grignard reagents, which not only enriches the chemistry of sulfones, but also provides a novel and practical synthetic tool towards N-heteroaromatic fluoroalkylation.

N‐Heteroaromatic Fluoroalkylation through Ligand Coupling Reaction of Sulfones

AbstractLigand coupling on hypervalent main group elements has emerged as a pivotal methodology for the synthesis of functionalized N‐heteroaromatic compounds in recent years due to the avoidance of transition metals and the mildness of the reaction conditions. In this direction, the reaction of N‐heteroaryl sulfur(IV) and N‐heteroaryl phosphorus(V) compounds has been well studied. However, the ligand coupling of sulfur(VI) is still underdeveloped and the reaction of alkyl N‐heteroarylsulfones is still elusive, which does not match the high status of sulfones as the chemical chameleons in organic synthesis. Here we present a ligand coupling‐enabled formal SO2 extrusion of fluoroalkyl 2‐azaheteroarylsulfones under the promotion of Grignard reagents, which not only enriches the chemistry of sulfones, but also provides a novel and practical synthetic tool towards N‐heteroaromatic fluoroalkylation.

Frontispiece: Sulfones as Chemical Chameleons: Versatile Synthetic Equivalents of Small‐Molecule Synthons

Just as a change in physical surroundings can prompt a chameleon to alter its color, a change in reaction conditions can cause a sulfonyl group to alter its chemical reactivity. This remarkable flexibility makes molecules bearing multiple sulfones incredibly versatile building blocks. In this Minireview by B. M. Trost et al. on page 11193 ff., the unique ability of 1,1- and 1,2-bis(sulfones) to masquerade as a vast array of reactive synthons, including methane polyanions, vinyl cations, and all-carbon dipoles, is highlighted.

Sulfones as Chemical Chameleons: Versatile Synthetic Equivalents of Small-Molecule Synthons.

Sulfones are flexible functional groups that can act as nucleophiles, electrophiles, or even radicals. Changing the reaction conditions can completely alter the reactivity of a sulfonyl group, and as a result, molecules bearing multiple sulfones are versatile building blocks. This Review highlights the unique ability of 1,1- and 1,2-bis(sulfones) to masquerade as a vast array of reactive synthons including methane polyanions, vinyl cations, and all-carbon dipoles that would be difficult or impossible to access directly.

New Psychoactive Substances: “Chemical Chameleons” That Evade Detection and Legislations

Background: New Psychoactive Substances (NPS) and New Emergent Substances (NES), are subversive and withering substances that invaded all communities around the globe without exceptions or immunity. They are being sold as recreational drugs containing synthetically designed substances, despite the tag label states “Not for Humans Use (e.g. bath salts, synthetic cannabinoids)1,2.Objective: The main theme and aim of this paper is to enhance and add to the huge efforts of different international and national organizations, government and law enforcement authorities to combat the spread and highlight the risks and serious implications of these substances on the health of humans and their wellbeing. Method: literature review was undertaken, with especially focus on the published data related to the objective of the paper. Some reference textbooks were also consulted, especially for the information regarding the laboratory techniques. Literature search was conducted using PubMed, EMBASE, PsycInfo, Internet underground and governmental websites using the following keywords alone or in combination: designer drugs, club drugs, party drugs, GHB, synthetic cathinones, mephedrone, methylone, flephedrone, MDAI, and MDVP. Conclusion: These substances pose a global threat that will affect young generations due to the health risks associated with the consumption of these drugs. This phenomenon requires the collaboration between the international organizations, the national reference laboratories, legislation authorities, law enforcement officers and political systems in the different countries to make the necessary plans and measures capable of stopping the production and distribution of these substances.

Indole synthesis: palladium-catalyzed C–H bond amination via reduction of nitroalkenes with carbon monoxide

Nitroalkenes have been called ‘chemical chameleons’ due to their versatility in numerous synthetic transformations. Herein, we describe the first transition metal-catalyzed transformation of conjugated nitroalkenes into indoles. Under mild reaction conditions (1 atm carbon monoxide, 110 °C), palladium catalyzes the reductive cyclization of nitroalkenes to form a putative nitrosoalkene intermediate, which then rearranges to provide 3-arylindoles in high yields. Notably, this novel C–H bond amination takes advantage of carbon monoxide as an inexpensive stoichiometric reductant and produces carbon dioxide as the major byproduct.

Cover Picture: Supramolecular Aggregates of Dendritic Multishell Architectures as Universal Nanocarriers (Angew. Chem. Int. Ed. 8/2007)

Chemical chameleons is an apt description for a new class of dendritic multishell architectures that exhibit universal transport properties for a variety of guest molecules in a broad range of solvent environments. In their Communication on page 1265 ff., R. Haag and co‐workers describe a supramolecular aggregation phenomenon that is responsible for the unique ability of these dendritic multishell architectures to encapsulate polar and nonpolar guests.

Supramolecular Aggregates of Dendritic Multishell Architectures as Universal Nanocarriers

Chemical chameleons: Highly stable supramolecular aggregates built from dendritic multishell architectures show a universal transport ability for both polar and nonpolar guest molecules and can adapt to various solvent environments, ranging from toluene to water.

Sulfoximines: Structures, Properties and Synthetic Applications

This review presents a comprehensive treatment of sulfoximine chemistry particularly emphasising synthetic developments and structural work after 1985. Following a brief introduction, the structures and properties of sulfoximines and metallated sulfoximines are discussed. The second section deals with the preparation of sulfoximines emphasising new methods. The main part of the review is concerned with reactions of sulfoximines. The material in this section is organised based on the reactivity pattern displayed by the various sulfoximines. Therefore they are grouped roughly into three classes of compounds. The first group of sulfoximines comprises compounds acting as C-nucleophiles, the second one contains electrophilic sulfoximines and the last group is made up of sulfoximines being useful as (chiral) ligands particularly for transition metals. Finally the ability of sulfoximines to act as "chiral chemical chameleons" and their rôle in biological and medicinal chemistry is briefly discussed.

CO Oxidation and NO Reduction on Perovskite Oxides

Abstract The search for substitutes of noble metal supported exhaust control catalysts has led to the study of a number of perovskite oxides (1). The mechanisms of redox processes on these surfaces are topotactic in nature, thus accounting forthe reversible loss and uptake of bulk oxygen or for the concomitant creation and annihilation of vacancies rendering these systems as attractive oxidation catalysts. The variable oxygen stoichiometry of perovskite structure is responsible for the exotic behavior of these materials as a new class of high Tc superconducting oxides (2). The extreme ease of removing oxygen from the framework but still retaining the basic ingredients of the perovskite structure and the possibility of deriving different structural frameworks from ideal perovskite structure (e.g. insertion of rock salt layer between perovskite layers results in a K2NiF4 structure, while insertion of double [Bi2O2] layers between perovskite layers results in an Aurivillius phase) and the possibility of substitution of either or both A and B site cations by foreign metal ions make them function as chemical chameleons (3) with a wide variety of solid state and catalytic properties. Among the various redox catalytic processes promoted by them the oxidation of CO and the reduction of NO seem to be interesting in view of their relevance for auto-exhaust emission control. The present chapter attempts to consider the generalities that have been evolved in these studies, which will be useful for the formulation of auto-exhaust control catalysts based on perovskites in the future.

N-Nitrosulfoximines as Chemical Chameleons for Asymmetric Synthesis

In contrast to N-tosylsulfoximines, the relatively obscure N-nitrosulfoximines show good diastereoselectivity in alkylations and extraordinarily good leaving group properties in cyclizations via SN2 displacement. Thus, methyl phenyl N-nitrosulfoximine serves as a chiral lynchpin for construction of chiral ring systems.

ChemInform Abstract: An Asymmetric Approach to 2‐Deoxynucleosides via Organosulfur Building Blocks as Chemical Chameleons.

AbstractChemInform 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.

Chemical chameleons: hydrogen bonding with imides and lactams in chloroform

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical chameleons: hydrogen bonding with imides and lactams in chloroformWilliam L. Jorgensen and Daniel L. SeveranceCite this: J. Am. Chem. Soc. 1991, 113, 1, 209–216Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published inissue 1 January 1991https://doi.org/10.1021/ja00001a030RIGHTS & PERMISSIONSArticle Views413Altmetric-Citations73LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (4 MB) Get e-Alerts Get e-Alerts

An asymmetric approach to 2-deoxynucleosides via organosulfur building blocks as chemical chameleons

An asymmetric synthesis of 6- N-benzoyl-5′- O-benzyl-2′-deoxyadenosine and its a anomer from non-carbohydrate building blocks is achieved in 7 steps. The sequence builds the basic structures using bis(methylthio)methane and methylthiomethyl phenyl sulfone as both nucleophilic and electrophilic building blocks, a feature that suggests their behavior as chemical chameleons. The asymmetric induction is achieved utilizing a kinetic resolution based upon catalytic asymmetric epoxidation.

ChemInform Abstract: Chemical Chameleons. Organosulfones as Synthetic Building Blocks

An overview of the duality of function of organosulfones as nucleophiles in basic media and electrophiles in Lewis acidic media, a change of reactivity for which they have been dubbed “chemical chameleons,” is presented. In the first phase, transition metal catalysts activate allyl sulfones towards displacements. Use of palladium, molybdenum, and nickel catalysts allow stabilized anions to effect displacement; copper catalysts allow non-stabilized nucleophiles to be used. The use of the anion stabilizing and leaving group abilities of sulfones created a novel three carbon intercalation and a novel cyclocontraction-spiroannulation in which β-hydroxy sulfones participate in a Lewis acid catalyzed pinacol rearrangement. The lability of allyl and tertiary sulfones towards Lewis acids creates a wide array of electrophilic reactions such as Friedel–Crafts type cyclizations, intermolecular alkylations with organoalanes and enol silyl ethers, and ring expansions. The ability to design novel reagents for synthesis...

Chemical Chameleons. Organosulfones as Synthetic Building Blocks

Abstract An overview of the duality of function of organosulfones as nucleophiles in basic media and electrophiles in Lewis acidic media, a change of reactivity for which they have been dubbed “chemical chameleons,” is presented. In the first phase, transition metal catalysts activate allyl sulfones towards displacements. Use of palladium, molybdenum, and nickel catalysts allow stabilized anions to effect displacement; copper catalysts allow non-stabilized nucleophiles to be used. The use of the anion stabilizing and leaving group abilities of sulfones created a novel three carbon intercalation and a novel cyclocontraction-spiroannulation in which β-hydroxy sulfones participate in a Lewis acid catalyzed pinacol rearrangement. The lability of allyl and tertiary sulfones towards Lewis acids creates a wide array of electrophilic reactions such as Friedel–Crafts type cyclizations, intermolecular alkylations with organoalanes and enol silyl ethers, and ring expansions. The ability to design novel reagents for synthesis based upon this dual reactivity of organosulfones is illustrated by the use of an alkoxy-bis(phenylsulfonyl)methane as a synthon for a carbonyl 1,1-dipole.

ChemInform Abstract: Organosulfones as Chemical Chameleons. A Ring Expansion to α‐Methoxy and α‐Phenylthio Ketones.

AbstractAddition of the α‐phenylthio sulfone (IV) to the ketone (I) gives the adduct (II), which undergoes rearrangement to the phenylthio ketone (III).

Organosulfones as chemical chameleons. Ring expansion to .alpha.-methoxy and .alpha.-phenylthio ketones

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrganosulfones as chemical chameleons. Ring expansion to .alpha.-methoxy and .alpha.-phenylthio ketonesBarry M. Trost and Gamal K. MikhailCite this: J. Am. Chem. Soc. 1987, 109, 13, 4124–4127Publication Date (Print):June 1, 1987Publication History Published online1 May 2002Published inissue 1 June 1987https://doi.org/10.1021/ja00247a055RIGHTS & PERMISSIONSArticle Views493Altmetric-Citations58LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (441 KB) Get e-Alerts Get e-Alerts

Sulfones as chemical chameleons. Cyclization via 1,1-dipole synthons

Sulfones as chemical chameleons. Cyclization via 1,1-dipole synthons