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Chemical Reviews Aug 2021This Review describes the development of strategies for carbonyl-olefin metathesis reactions relying on stepwise, stoichiometric, or catalytic approaches. A... (Review)
Review
This Review describes the development of strategies for carbonyl-olefin metathesis reactions relying on stepwise, stoichiometric, or catalytic approaches. A comprehensive overview of currently available methods is provided starting with Paternò-Büchi cycloadditions between carbonyls and alkenes, followed by fragmentation of the resulting oxetanes, metal alkylidene-mediated strategies, [3 + 2]-cycloaddition approaches with strained hydrazines as organocatalysts, Lewis acid-mediated and Lewis acid-catalyzed strategies relying on the formation of intermediate oxetanes, and protocols based on initial carbon-carbon bond formation between carbonyls and alkenes and subsequent Grob-fragmentations. The Review concludes with an overview of applications of these currently available methods for carbonyl-olefin metathesis in complex molecule synthesis. Over the past eight years, the field of carbonyl-olefin metathesis has grown significantly and expanded from stoichiometric reaction protocols to efficient catalytic strategies for ring-closing, ring-opening, and cross carbonyl-olefin metathesis. The aim of this Review is to capture the status quo of the field and is expected to contribute to further advancements in carbonyl-olefin metathesis in the coming years.
Topics: Alkenes; Carbon; Catalysis; Cycloaddition Reaction; Lewis Acids
PubMed: 34133136
DOI: 10.1021/acs.chemrev.0c01096 -
Angewandte Chemie (International Ed. in... Aug 2022The asymmetric hydroaminocarbonylation of olefins represents a straightforward approach for the synthesis of enantioenriched amides, but is hampered by the necessity to...
The asymmetric hydroaminocarbonylation of olefins represents a straightforward approach for the synthesis of enantioenriched amides, but is hampered by the necessity to employ CO gas, often at elevated pressures. We herein describe, as an alternative, an enantioselective hydrocarbamoylation of alkenes leveraging dual copper hydride and palladium catalysis to enable the use of readily available carbamoyl chlorides as a practical carbamoylating reagent. The protocol is applicable to various types of olefins, including alkenyl arenes, terminal alkenes, and 1,1-disubstituted alkenes. Substrates containing a diverse range of functional groups as well as heterocyclic substructures undergo functionalization to provide α- and β-chiral amides in good yields and with excellent enantioselectivities.
Topics: Alkenes; Amides; Catalysis; Molecular Structure; Palladium; Stereoisomerism
PubMed: 35657208
DOI: 10.1002/anie.202206692 -
Chemistry (Weinheim An Der Bergstrasse,... Oct 2022Herein we report a photo-mediated formal addition of carboxylic acids to activated alkenes catalyzed by a pyrimidopteridine photoredox catalyst. The decarboxylation of...
Herein we report a photo-mediated formal addition of carboxylic acids to activated alkenes catalyzed by a pyrimidopteridine photoredox catalyst. The decarboxylation of aliphatic carboxylic acids upon single-electron oxidation is countered in the presence of electron-rich alkenes and a hydroacetoxylation is observed. Mechanistic proposals have been made based on CV measurements, competitive Stern-Volmer quenching and EPR experiments. Evidence that tetra-N-substituted pyrimidopteridines function as dual photoredox and hydrogen atom transfer catalyst was supported by spectroscopic means.
Topics: Alkenes; Carboxylic Acids; Catalysis; Hydrogen; Oxidation-Reduction
PubMed: 35916156
DOI: 10.1002/chem.202201761 -
Angewandte Chemie (International Ed. in... Oct 2022Molecular machines are at the frontier of biology and chemistry. The ability to control molecular motion and emulating the movement of biological systems are major steps... (Review)
Review
Molecular machines are at the frontier of biology and chemistry. The ability to control molecular motion and emulating the movement of biological systems are major steps towards the development of responsive and adaptive materials. Amazing progress has been seen for the design of molecular machines including light-induced unidirectional rotation of overcrowded alkenes. However, the feasibility of inducing unidirectional rotation about a single bond as a result of chemical conversion has been a challenging task. In this Review, an overview of approaches towards the design, synthesis, and dynamic properties of different classes of atropisomers which can undergo controlled switching or rotation under the influence of a chemical stimulus is presented. They are categorized as molecular switches, rotors, motors, and autonomous motors according to their type of response. Furthermore, we provide a future perspective and challenges focusing on building sophisticated molecular machines.
Topics: Alkenes; Rotation; Smart Materials
PubMed: 35852813
DOI: 10.1002/anie.202206631 -
Molecules (Basel, Switzerland) Aug 2022Among the variety of sulfonamides, triflamides (CFSONHR, TfNHR) occupy a special position in organic chemistry. Triflamides are widely used as reagents, efficient... (Review)
Review
Among the variety of sulfonamides, triflamides (CFSONHR, TfNHR) occupy a special position in organic chemistry. Triflamides are widely used as reagents, efficient catalysts or additives in numerous reactions. The reasons for the widespread use of these compounds are their high NH-acidity, lipophilicity, catalytic activity and specific chemical properties. Their strong electron-withdrawing properties and low nucleophilicity, combined with their high NH-acidity, makes it possible to use triflamides in a vast variety of organic reactions. This review is devoted to the synthesis and use of -trifluoromethanesulfonyl derivatives in organic chemistry, medicine, biochemistry, catalysis and agriculture. Part of the work is a review of areas and examples of the use of bis(trifluoromethanesulfonyl)imide (triflimide, (CFSO)NH, TfNH). Being one of the strongest NH-acids, triflimide, and especially its salts, are widely used as catalysts in cycloaddition reactions, Friedel-Crafts reactions, condensation reactions, heterocyclization and many others. Triflamides act as a source of nitrogen in C-amination (sulfonamidation) reactions, the products of which are useful building blocks in organic synthesis, catalysts and ligands in metal complex catalysis, and have found applications in medicine. The addition reactions of triflamide in the presence of oxidizing agents to alkenes and dienes are considered separately.
Topics: Alkenes; Catalysis; Cyclohexanones; Molecular Structure
PubMed: 36014447
DOI: 10.3390/molecules27165201 -
Journal of the American Chemical Society Dec 2020A user-friendly approach is presented to sidestep the venerable Grignard addition to unactivated ketones to access tertiary alcohols by reversing the polarity of the...
A user-friendly approach is presented to sidestep the venerable Grignard addition to unactivated ketones to access tertiary alcohols by reversing the polarity of the disconnection. In this work a ketone instead acts as a nucleophile when adding to simple unactivated olefins to accomplish the same overall transformation. The scope of this coupling is broad as enabled using an electrochemical approach, and the reaction is scalable, chemoselective, and requires no precaution to exclude air or water. Multiple applications demonstrate the simplifying nature of the reaction on multistep synthesis, and mechanistic studies point to an intuitive mechanism reminiscent of other chemical reductants such as SmI (which cannot accomplish the same reaction).
Topics: Alkenes; Catalysis; Electron Transport; Ketones
PubMed: 33259715
DOI: 10.1021/jacs.0c11214 -
Chemical Reviews Dec 2021Asymmetric hydroalkoxylation of alkenes constitutes a redox-neutral and 100% atom-economical strategy toward enantioenriched oxygenated building blocks from readily... (Review)
Review
Asymmetric hydroalkoxylation of alkenes constitutes a redox-neutral and 100% atom-economical strategy toward enantioenriched oxygenated building blocks from readily available starting materials. Despite their great potential, catalytic enantioselective additions of alcohols across a C-C multiple bond are particularly underdeveloped, especially compared to other hydrofunctionalization methods such as hydroamination. However, driven by some recent innovations, e.g., asymmetric MHAT methods, asymmetric photocatalytic methods, and the development of extremely strong chiral Brønsted acids, there has been a gratifying surge of reports in this burgeoning field. The goal of this review is to survey the growing landscape of asymmetric hydroalkoxylation by highlighting exciting new advances, deconstructing mechanistic underpinnings, and drawing insight from related asymmetric hydroacyloxylation and hydration. A deep appreciation of the underlying principles informs an understanding of the various selectivity parameters and activation modes in the realm of asymmetric alkene hydrofunctionalization while simultaneously evoking the outstanding challenges to the field moving forward. Overall, we aim to lay a foundation for cross-fertilization among various catalytic fields and spur further innovation in asymmetric hydroalkoxylations of C-C multiple bonds.
Topics: Acids; Alkenes; Catalysis; Oxidation-Reduction; Stereoisomerism
PubMed: 34860509
DOI: 10.1021/acs.chemrev.1c00620 -
Molecules (Basel, Switzerland) Feb 2020Unsymmetrical 1,1-bis(boryl)alkanes and alkenes are organo-bismetallic equivalents, which are synthetically important because they allow for sequential selective... (Review)
Review
Unsymmetrical 1,1-bis(boryl)alkanes and alkenes are organo-bismetallic equivalents, which are synthetically important because they allow for sequential selective transformations of C-B bonds. We reviewed the synthesis and chemical reactivity of 1,1bis(boryl)alkanes and alkenes to provide information for the synthetic community. In the first part of this review, we disclose the synthesis and chemical reactivity of unsymmetrical 1,1-bisborylalkanes. In the second part, we describe the synthesis and chemical reactivity of unsymmetrical 1,1-bis(boryl)alkenes.
Topics: Alkenes; Boron Compounds
PubMed: 32093409
DOI: 10.3390/molecules25040959 -
Angewandte Chemie (International Ed. in... Jan 2023A catalysis-based regioselective 1,4-fluorofunctionalization of trifluoromethyl substituted 1,3-dienes has been developed to access compact, highly functionalized...
A catalysis-based regioselective 1,4-fluorofunctionalization of trifluoromethyl substituted 1,3-dienes has been developed to access compact, highly functionalized products. The process allows E,Z-mixed dienes to be processed to a single E-alkene isomer, and leverages an inexpensive and operationally convenient I(I)/I(III) catalysis platform. The first example of catalytic 1,4-difluorination is disclosed and subsequently evolved to enable 1,4-hetero-difunctionalization, which allows δ-fluoro-alcohol and amine derivatives to be forged in a single operation. The protocol is compatible with a variety of nucleophiles including fluoride, nitriles, carboxylic acids, alcohols and even water thereby allowing highly functionalized products, with a stereocenter bearing both C(sp )-F and C(sp )-CF groups, to be generated rapidly. Scalability (up to 3 mmol), and facile post-reaction modifications are demonstrated to underscore the utility of the method in expanding organofluorine chemical space.
Topics: Polyenes; Isomerism; Alkenes; Catalysis; Alcohols
PubMed: 36345795
DOI: 10.1002/anie.202214906 -
Chemistry, An Asian Journal Jun 2022Alkene amino(hetero)arylation presents a highly efficient and straightforward strategy for direct installation of amino groups and heteroaryl rings across a double bond... (Review)
Review
Alkene amino(hetero)arylation presents a highly efficient and straightforward strategy for direct installation of amino groups and heteroaryl rings across a double bond simultaneously. An extensive array of practical transformations has been developed via alkene difunctionalization approach to access a broad range of medicinally valuable (hetero)arylethylamine motifs. This review presents recent progress in 1,2-amino(hetero)arylation of alkenes organized in three different modes. First, intramolecular transformations employing C, N-tethered alkenes will be introduced. Next, two-component reactions will be discussed with different combination of precursors, N-tethered alkenes and external aryl precursor, C-tethered alkenes and external amine precursor, or C, N-tethered reagents, and alkenes. Last, three-component intermolecular amino(hetero)arylation reactions will be covered.
Topics: Alkenes; Amination; Amines; Catalysis
PubMed: 35460596
DOI: 10.1002/asia.202200215