Enantioselective Copper-Catalyzed Ring-Opening Diboration of Arylidenecyclopropanes to Access Chiral Skipped 1,4- and 1,3-Diboronates

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(8), P. 5366 - 5374

Published: Feb. 14, 2024

Two enantioselective approaches to synthesize chiral skipped diboronate compounds have been developed, relying on copper-catalyzed one-pot asymmetric ring-opening diboration of arylidenecyclopropanes. A wide range arylidenecyclopropanes react smoothly with HBpin in the presence CuOAc and (R)-DTBM-Segphos, affording 1,4-diboronates high enantioselectivity (up 99% ee). Meanwhile, a variety selectively B2pin2 (S,S)-Ph-BPE sequential addition MeOH, providing 1,3-diboronates 98% These enantioenriched 1,3- can undergo various enantiospecific transformations minimal loss their enantiopurity. Mechanistic studies reveal that these two processes start CuH-catalyzed hydroboration form mixture Z/E-homoallyl boronate intermediates, which subsequently second or Cu-Bpin-catalyzed protoboration produce 1,3-diboronates, respectively.

Language: Английский

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Palladium‐Catalyzed Defluorinative Alkylation of gem‐Difluorocyclopropanes: Switching Regioselectivity via Simple Hydrazones

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(23), P. 13098 - 13104

Published: March 23, 2021

Abstract Conventional approaches for Pd‐catalyzed ring‐opening cross‐couplings of gem ‐difluorocyclopropanes with nucleophiles predominantly deliver the β‐fluoroalkene scaffolds (linear selectivity). Herein, we report a cooperative strategy that can completely switch reaction selectivity to give alkylated α‐fluoroalkene skeletons (branched The unique reactivity hydrazones enables analogous inner‐sphere 3,3′‐reductive elimination driven by denitrogenation, as well assistance steric‐embedded N ‐heterocyclic carbene ligand, are key regioselectivity. A wide range derived from naturally abundant aryl and alkyl aldehydes applicable, various ‐difluorocyclopropanes, including modified pharmaceutical biological molecules, be efficiently functionalized high value α‐fluorinated alkene motifs under mild conditions.

Language: Английский

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Carbonyl umpolung as an organometallic reagent surrogate

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(19), P. 10733 - 10742

Published: Jan. 1, 2021

Carbonyls can serve as surrogates for organometallic reagents via hydrazones.

Language: Английский

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Catalytic Generation of Carbanions through Carbonyl Umpolung

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(40), P. 21624 - 21634

Published: May 15, 2021

Abstract Carbonyl Umpolung is a powerful strategy in organic chemistry to construct complex molecules. Over the last few years, versatile catalytic approaches for generation of acyl anion equivalents from carbonyl compounds have been developed, but methods obtain alkyl carbanions fashion are still at an early stage. This Minireview summarizes recent progress through Umpolung. Two different can be utilized enable compounds: Wolff–Kishner reaction and single‐electron reduction imines. We discuss scope, mechanistic insights, synthetic applications as well potential future developments.

Language: Английский

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Deoxygenative Functionalizations of Aldehydes, Ketones and Carboxylic Acids

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 61(10)

Published: Nov. 15, 2021

The simple and efficient conversion of carbonyl compounds into functionalized alkanes via deoxygenation is highly enabling in chemical synthesis. This Review covers the recent methodology development carboxyl deoxygenative functionalizations, highlighting some representative significant contributions this field. These advances are categorized based on reactivity patterns oxygenated feedstock compounds, including aldehydes, ketones carboxylic acids. Four types reactive intermediates arising from aldehydes during deoxygenation, namely, bis-electrophiles, carbenoids, bis-nucleophiles alkyl radical equivalents, presented, while acids mainly behave as tris-electrophiles when deoxygenated. In each subcategory, selected examples organized according to type bond formation discussed a generalized mechanistic perspective.

Language: Английский

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Palladium‐Catalyzed Enantio‐ and Regioselective Ring‐Opening Hydrophosphinylation of Methylenecyclopropanes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(26)

Published: April 26, 2023

Transition metal-catalyzed hydrofunctionalization of methylenecyclopropanes (MCPs) has presented a considerable challenge due to the difficult manipulation regioselectivity and complicated reaction patterns. Herein, we report straightforward Pd-catalyzed ring-opening hydrophosphinylation MCPs via highly selective C-C bond cleavage. This method allows for rapid efficient access wide range chiral allylic phosphine oxides in good yields high enantioselectivities. Additionally, density functional theory (DFT) calculations were performed elucidate mechanism origin enantioselectivity.

Language: Английский

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Enantio‐ and Regioselective Construction of 1,4‐Diamines via Cascade Hydroamination of Methylene Cyclopropanes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(24)

Published: March 26, 2022

Abstract Despite the widespread existence of chiral 1,4‐diamines in bioactive molecules and their applications asymmetric catalysis, catalytic synthesis such structures from readily accessible substrates remains a long‐standing challenge. Here, we report Cu‐catalyzed cascade hydroamination protocol to construct wide range 1,4‐diamine derivatives high yields with excellent enatioselectivities (up 95 % yield up >99 ee). The use two hydroxylamine esters containing different functionalized amino groups allowed us increase complexity final structures. desired products could be easily transformed into NH 2 ‐Terfenadine. Mechanistic study demonstrates that this reaction proceeds through ring‐opening sequence.

Language: Английский

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Enantioselective 1,4-Borylamination via Copper-Catalyzed Cascade Hydroborylation and Hydroamination of Arylidenecyclopropanes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(47), P. 32283 - 32291

Published: Nov. 13, 2024

Compounds bearing both boryl and amino groups at distal positions are invaluable synthons for synthesizing pharmaceuticals, drug candidates, natural products, but their catalytic enantioselective synthesis remains rarely explored. We report the first 1,4-borylamination reaction through a copper-catalyzed cascade hydroborylation hydroamination of arylidenecyclopropanes. This combines four readily available components in highly chemo-, site-, fashion (>20:1 r.r. up to 99% ee), yielding diverse array synthetically valuable enantioenriched 4-amino alkylboronates. The versatile utility these products is highlighted by transformations wide applications pharmaceutical discovery. Preliminary mechanistic studies were conducted elucidate operative pathway, intermediates, origins its high chemo- site-selectivity.

Language: Английский

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Visible-light-mediated deoxygenative transformation of 1,2-dicarbonyl compounds through energy transfer process

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Oct. 25, 2024

Language: Английский

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Electrochemical deoxygenative reduction of ketones

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(79), P. 11155 - 11158

Published: Jan. 1, 2022

Electrochemical reduction via paired electrolysis has been used to achieve deoxygenative of ketones. As a result the complexing ketones with triphenylphosphine radical cation generated by anodic oxidation, carbonyl groups occurs readily. Through spontaneous β-scission phosphoranyl radicals, C-O bonds are cleaved form benzylic intermediates. These species either able abstract hydrogen from MeCN or undergo at cathode give carbanions, upon workup forming reductive hydrogenation

Language: Английский

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