Fluorochemicals from fluorspar via a phosphate-enabled mechanochemical process that bypasses HF

Science, Journal Year: 2023, Volume and Issue: 381(6655), P. 302 - 306

Published: July 20, 2023

All fluorochemicals—including elemental fluorine and nucleophilic, electrophilic, radical fluorinating reagents—are prepared from hydrogen fluoride (HF). This highly toxic corrosive gas is produced by the reaction of acid-grade fluorspar (>97% CaF 2 ) with sulfuric acid under harsh conditions. The use to produce fluorochemicals via a process that bypasses HF desirable but remains an unsolved problem because prohibitive insolubility . Inspired calcium phosphate biomineralization, we herein disclose protocol treating dipotassium (K HPO 4 mechanochemical affords solid composed crystalline K 3 (HPO )F 2− x Ca y (PO F) b , which found suitable for forging sulfur-fluorine carbon-fluorine bonds.

Language: Английский

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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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Desymmetrization of Vicinal Bis(boronic) Esters by Enantioselective Suzuki–Miyaura Cross-Coupling Reaction

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(15), P. 8308 - 8313

Published: April 6, 2023

The development of an enantioselective catalytic Suzuki-Miyaura reaction that applies to

Language: Английский

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Nickel-Catalyzed Regio- and Enantioselective Borylative Coupling of Terminal Alkenes with Alkyl Halides Enabled by an Anionic Bisoxazoline Ligand

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(25), P. 13603 - 13614

Published: June 6, 2023

Chiral boronic esters are a class of versatile building blocks. We describe herein an asymmetric nickel-catalyzed borylative coupling terminal alkenes with nonactivated alkyl halides. The success this reaction is ascribed to the application chiral anionic bisoxazoline ligand. This study provides three-component strategy access α- and β-stereogenic from easily accessible starting materials. protocol characterized by mild conditions, wide substrate scope high regio- enantioselectivity. also showcase value method in simplifying synthesis several drug molecules. Mechanistic studies suggest that generation enantioenriched bearing α-stereogenic center results stereoconvergent process, while enantioselectivity-controlling step β-stereocenter switched olefin migratory insertion due coordination ester group.

Language: Английский

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Asymmetric Synthesis of Chiral 1,2‐Bis(Boronic) Esters Featuring Acyclic, Non‐Adjacent 1,3‐Stereocenters

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(5)

Published: Dec. 15, 2023

The construction of acyclic, non-adjacent 1,3-stereogenic centers, prevalent motifs in drugs and bioactive molecules, has been a long-standing synthetic challenge due to acyclic nucleophiles being distant from the chiral environment. In this study, we successfully synthesized highly valuable 1,2-bis(boronic) esters featuring nonadjacent 1,3-stereocenters. Notably, reaction selectively produces migratory coupling products rather than alternative deborylative allylation or direct byproducts. This approach introduces new activation mode for selective transformations gem-diborylmethane asymmetric catalysis. Additionally, found that other gem-diborylalkanes, previously challenging steric hindrance, also participated reaction. incorporation 1,2-bis(boryl)alkenes facilitated diversification alkenyl two boron moieties our target compounds, thereby enabling access broad array versatile molecules. DFT calculations were performed elucidate mechanism shed light on factors responsible observed excellent enantioselectivity diastereoselectivity. These determined arise ligand-substrate repulsions syn-addition transition state.

Language: Английский

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Updated Progress of the Copper-Catalyzed Borylative Functionalization of Unsaturated Molecules

Molecules, Journal Year: 2023, Volume and Issue: 28(5), P. 2252 - 2252

Published: Feb. 28, 2023

Borylation has become a powerful method to synthesize organoboranes as versatile building blocks in organic synthesis, medicinal chemistry, and materials science. Copper-promoted borylation reactions are extremely attractive due the low cost non-toxicity of copper catalyst, mild reaction conditions, good functional group tolerance, convenience chiral induction. In this review, we mainly updated recent advances (from 2020 2022) synthetic transformations C=C/C≡C multiple bonds, C=E bonds mediated by boryl systems.

Language: Английский

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Stereospecific Transformations of Alkylboronic Esters Enabled by Direct Boron-to-Zinc Transmetalation

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(18), P. 9976 - 9981

Published: April 26, 2023

Chiral secondary organoboronic esters, when activated with t-butyllithium, are shown to undergo efficient stereoretentive transmetalation either zinc acetate or chloride. This reaction provides chiral alkylzinc reagents that configurationally stable under practical experimental conditions. The organozinc compounds were found engage in stereospecific reactions difluorocarbene, catalytic cross-couplings palladium-based catalysts, and trifluoromethylation a copper(III) complex. Mechanistic computational studies shed light on the inner workings of event.

Language: Английский

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Enantioselective Suzuki cross-coupling of 1,2-diboryl cyclopropanes

Chemical Science, Journal Year: 2023, Volume and Issue: 14(6), P. 1575 - 1581

Published: Jan. 1, 2023

Herein, we describe the catalytic enantioselective cross-coupling of 1,2-bisboronic esters. Prior work on group specific cross coupling is limited to use geminal bis-boronates. This desymmetrization provides a novel approach prepare enantioenriched cyclopropyl boronates with three contiguous stereocenters, that could be further derivatized through selective functionalization carbon-boron bond. Our results suggest transmetallation, which enantiodetermining step, takes place retention stereochemistry at carbon.

Language: Английский

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Mechanistic Study of the Copper(II)-Mediated Site-Selective O-Arylation of Glycosides with Arylboronic Acids

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(6), P. 3487 - 3498

Published: March 8, 2023

Glycosides having multiple free OH groups have been shown to undergo site-selective O-arylations in the presence of arylboronic acids and copper(II) acetate. Herein, a mechanistic analysis these Chan–Evans–Lam-type couplings is presented based on reaction kinetics, mass spectrometric mixtures, substituent effect studies. The results establish that formation substrate-derived boronic ester accelerates rate-determining transmetalation step. Intramolecular transfer aryl group from ruled out favor pathway which key pre-transmetalation assembly generated ester, copper complex, second equivalent acid.

Language: Английский

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Catalytic asymmetric synthesis of meta benzene isosteres

Nature, Journal Year: 2024, Volume and Issue: 633(8028), P. 90 - 95

Published: Aug. 21, 2024

Language: Английский

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