Intermolecular Metal-Catalyzed Reductive Coupling of Dienes, Allenes, and Enynes with Carbonyl Compounds and Imines

Chemical Reviews, Journal Year: 2018, Volume and Issue: 118(12), P. 6026 - 6052

Published: June 13, 2018

Metal-catalyzed reductive coupling has emerged as an alternative to the use of stoichiometric organometallic reagents in increasingly diverse range carbonyl and imine additions. In this review, diene, allene, enyne pronucleophiles intermolecular couplings are surveyed, along with related hydrogen autotransfer processes.

Language: Английский

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Acyclic Quaternary Carbon Stereocenters via Enantioselective Transition Metal Catalysis

Chemical Reviews, Journal Year: 2017, Volume and Issue: 117(19), P. 12564 - 12580

Published: Sept. 14, 2017

Whereas numerous asymmetric methods for formation of quaternary carbon stereocenters in cyclic systems have been documented, the construction acyclic with control absolute stereochemistry remains a formidable challenge. This Review summarizes enantioselective from achiral or chiral racemic reactants via transition metal catalysis.

Language: Английский

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Catalytic Enantioselective Carbonyl Allylation and Propargylation via Alcohol-Mediated Hydrogen Transfer: Merging the Chemistry of Grignard and Sabatier

Accounts of Chemical Research, Journal Year: 2017, Volume and Issue: 50(9), P. 2371 - 2380

Published: Aug. 9, 2017

Merging the characteristics of transfer hydrogenation and carbonyl addition, we have developed a new class catalytic enantioselective C-C bond formations. In these processes, hydrogen between alcohols π-unsaturated reactants generates carbonyl-organometal pairs that combine to deliver products addition. On basis this mechanistic paradigm, lower are converted directly higher in absence premetalated reagents or discrete alcohol-to-carbonyl redox reactions. certain cases, due pronounced kinetic preference for primary versus secondary alcohol dehydrogenation, diols polyols found engage stereo- site-selective formation-a capability further enhances efficiency by enabling skeletal construction events without extraneous manipulations devoted installation removal protecting groups. While Account focuses on redox-neutral couplings alcohols, corresponding aldehyde reductive mediated 2-propanol were parallel most transformations reported herein. Mechanistically, two distinct classes C-H functionalizations emerged, which distinguished mode pronucleophile activation, specifically, processes wherein oxidation is balanced (a) π-bond hydrometalation (b) C-X cleavage. Each pathway offers access allylmetal allenylmetal intermediates and, therefrom, enantiomerically enriched homoallylic homopropargylic products, respectively. broadest terms, addition has played central role synthetic organic chemistry well over century, but requisite organometallic pose issues safety, require multistep syntheses, generate stoichiometric quantities metallic byproducts. The concepts described Account, conceived wholly within author's laboratory, signal departure from use Rather, they reimagine as autotransfer process cross-coupling reactants, virtue their native reducing ability, drive generation transient nucleophiles doing so, serve dually proelectrophiles. allylative propargylative date display capabilities far beyond classical counterparts, application total synthesis type-I polyketide natural evoked step-change efficiency. More importantly, present data suggest diverse traditionally reliant may now be conducted catalytically metals. This provides reader potential practitioner with catalog alcohol-mediated additions-a user's guide, 10-year retrospective, foundation future work emerging area formation.

Language: Английский

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Iron-Catalyzed Methylation Using the Borrowing Hydrogen Approach

ACS Catalysis, Journal Year: 2018, Volume and Issue: 8(7), P. 6440 - 6445

Published: June 14, 2018

A general iron-catalyzed methylation has been developed using methanol as a C1 building block. This borrowing hydrogen approach employs Knölker-type (cyclopentadienone)iron carbonyl complex catalyst (2 mol %) and exhibits broad reaction scope. variety of ketones, indoles, oxindoles, amines, sulfonamides undergo mono- or dimethylation in excellent isolated yields (>60 examples, 79% average yield).

Language: Английский

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Metal-Catalyzed Intermolecular Hydrofunctionalization of Allenes: Easy Access to Allylic Structures via the Selective Formation of C–N, C–C, and C–O Bonds

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(24), P. 13545 - 13598

Published: Dec. 10, 2020

Following a strong regain of interest over the past 20 years in chemistry allenes, this "forgotten" family unsaturated molecules is undergoing renaissance. In context, metal-catalyzed hydrofunctionalization allenes nowadays one most studied transformations. The latter great because it opens way to produce selectively functionalized allylic structures. These motifs are important synthesis, particularly for formation asymmetric centers. Hydrofunctionalization also totally atom economical strategy, avoiding generation any waste, Compared main pathway obtain (aka Tsuji-Trost substitution), does not require prefunctionalization starting material with leaving group. This review presents state art exploration all existing transition methods allowing selective intermolecular N–H, C–H, and O–H nucleophiles or electrophiles.

Language: Английский

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Asymmetric, visible light-mediated radical sulfinyl-Smiles rearrangement to access all-carbon quaternary stereocentres

Nature Chemistry, Journal Year: 2021, Volume and Issue: 13(4), P. 327 - 334

Published: April 1, 2021

Language: Английский

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From Hydrogenation to Transfer Hydrogenation to Hydrogen Auto-Transfer in Enantioselective Metal-Catalyzed Carbonyl Reductive Coupling: Past, Present, and Future

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(9), P. 5572 - 5585

Published: April 22, 2021

Atom-efficient processes that occur via addition, redistribution or removal of hydrogen underlie many large volume industrial and pervade all segments chemical industry. Although carbonyl addition is one the oldest most broadly utilized methods for C-C bond formation, delivery non-stabilized carbanions to compounds has relied on premetalated reagents metallic/organometallic reductants, which pose issues safety challenges vis-à-vis implementation. Catalytic reductive couplings promoted hydrogenation, transfer hydrogenation auto-transfer allow abundant unsaturated hydrocarbons serve as substitutes organometallic reagents, enabling formation in absence stoichiometric metals. This perspective (a) highlights past milestones catalytic auto-transfer, (b) summarizes current enantioselective couplings, (c) describes future opportunities based patterns reactivity animate transformations this type.

Language: Английский

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Alcohols as Substrates in Transition-Metal-Catalyzed Arylation, Alkylation, and Related Reactions

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(9), P. 6078 - 6144

Published: April 17, 2024

Alcohols are abundant and attractive feedstock molecules for organic synthesis. Many methods their functionalization require them to first be converted into a more activated derivative, while recent years have seen vast increase in the number of complexity-building transformations that directly harness unprotected alcohols. This Review discusses how transition metal catalysis can used toward this goal. These broadly classified three categories. Deoxygenative functionalizations, representing derivatization C–O bond, enable alcohol act as leaving group formation new C–C bonds. Etherifications, characterized by O–H represent classical reactivity has been modernized include mild reaction conditions, diverse partners, high selectivities. Lastly, chain reactions described, wherein acts mediator formal C–H alkyl backbone. Each these classes transformation will discussed context intermolecular arylation, alkylation, related reactions, illustrating alcohols harnessed

Language: Английский

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A Regio- and Enantioselective CuH-Catalyzed Ketone Allylation with Terminal Allenes

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(6), P. 2007 - 2011

Published: Jan. 27, 2018

We report a method for the highly enantioselective CuH-catalyzed allylation of ketones that employs terminal allenes as allylmetal surrogates. Ketones and bearing diverse sensitive functional groups are efficiently coupled with high stereoselectivity exclusive branched regioselectivity. In stoichiometric experiments, each elementary step proposed hydrocupration–addition–metathesis mechanism can be followed by NMR spectroscopy.

Language: Английский

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Catalytic C₁ Alkylation with Methanol and Isotope‐Labeled Methanol

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(3), P. 775 - 779

Published: Nov. 20, 2018

Abstract A metal‐catalyzed methylation process has been developed. By employing an air‐ and moisture‐stable manganese catalyst together with isotopically labeled methanol, a series of D‐, CD 3 ‐, 13 C‐labeled products were obtained in good yields under mild reaction conditions water as the only byproduct.

Language: Английский

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