Atroposelective Synthesis of C−N Vinylindole Atropisomers by Palladium‐Catalyzed Asymmetric Hydroarylation of 1‐Alkynylindoles

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(45)

Published: Sept. 25, 2023

Transition-metal-catalyzed hydroarylation of unsymmetrical internal alkynes remains challenging because the difficulty in controlling regioselectivity and stereoselectivity. Moreover, enantioselective using organoboron reagents has not been reported. Herein, we report for first time that palladium compounds can catalyze 1-alkynylindoles with organoborons synthesis chiral C-N atropisomers. A series rarely reported vinylindole atropisomers was synthesized excellent regio-, stereo- (Z-selectivity), enantioselectivity under mild reaction conditions. The ready availability simplicity, high stereoselectivity, good functional group tolerance this catalytic system make it highly attractive.

Language: Английский

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Diversity-oriented synthesis of stereodefined tetrasubstituted alkenes via a modular alkyne gem-addition strategy

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 25, 2025

Abstract Stereocontrolled construction of tetrasubstituted olefins has been an attractive issue yet remains challenging for synthetic chemists. In this manuscript, alkynyl selenides, when treated with ArBCl 2 , are subject to exclusive 1,1-carboboration, affording alkenes excellent levels E -selectivity. Detailed mechanistic studies, supported by DFT calculations, elucidates the role selenium in 1,1-addition process. Coupled subsequent C-B and C-Se bond transformations, protocol constitutes a modular access stereodefined all-carbon alkenes. The merit approach is demonstrated programmed assembly diverse functionalized multi-arylated alkenes, especially enabling stereospecific synthesis all six possible stereoisomers tetraarylethene (TAE) derived from random permutation four distinct aryl substituents around double bond. diversity-oriented further utilized explore different TAE luminogenic properties potential Se-containing antitumor lead compounds.

Language: Английский

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Enantioselective Multicomponent Electrochemical Difunctionalization of Terminal Alkynes

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 25, 2025

The direct functionalization of alkyne triple bonds using a radical strategy provides an efficient platform for creating wide range substituted alkenes. However, developing multicomponent enantioselective reaction feedstock alkynes to forge all-carbon quaternary stereocenters─while addressing challenges related compatibility, selectivity, and efficiency─remains relatively rare. Here we report electrochemical nickel-catalyzed three-component cross-coupling readily available terminal alkynes, diverse racemic alkyl precursors, group transfer reagents (such as (TMS)3Si-H, RSe-SeR, RTe-TeR, CHI3), achieving excellent regio-, stereo-, enantioselectivities (more than 70 examples, up 95% ee). Electricity-mediated difunctionalizations significantly expand the scope both aliphatic aromatic demonstrating functional compatibility. key success lies in rational design anodically generated nickel-bound tertiary intermediates, which stereoselectively capture form vinyl radicals participate subsequently processes enable intermolecular anti-stereoselective difunctionalization alkynes. This approach allows transformation into structural entities with α-quaternary stereogenic centers.

Language: Английский

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Synthesis of Polysubstituted Aromatics via the Pd(II)-Initiated Borono-Catellani Reaction

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 6, 2025

Herein, we report a novel palladium(II)-initiated borono-Catellani reaction that utilizes widely accessible aryl boronic acids serve as both the reaction-initiating and -terminating substrates for first time. The was facilitated by cooperative catalysis between Pd(OAc)2 NBE, with air serving oxidizing agent, opening new venues developing Catellani-type reactions. Importantly, this method is compatible wide range of substrates, including naphthaleneboronic acid, phenylboric acid derivatives, alkyl iodides, under these environmentally friendly mild conditions, thereby demonstrating versatile functional group compatibility synthesis valuable polysubstituted aromatics.

Language: Английский

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Ligand-Controlled Enantioselective Copper-Catalyzed Hydroboration and Ring-Opening Dihydroboration of Arylidenecyclobutanes

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 25, 2025

Arylidenecyclobutanes are readily accessible and versatile reagents in synthetic chemistry due to the multifaceted reactivity exhibited by their alkene strained cyclobutane moieties. However, metal-catalyzed enantioselective functionalization of arylidenecyclobutanes, particularly controllable ring-retaining ring-opening reactions, is rarely explored. Considering utility enantioenriched organoboronate compounds, herein we report ligand-controlled copper-catalyzed hydroboration dihydroboration reactions arylidenecyclobutanes that afford chiral α-cyclobutyl benzylboronate 1,5-diboronate compounds with high enantioselectivity when (S)-DTBM-Segphos (S,S)-Ph-BPE employed, respectively. Mechanistic studies reveal process via β-C elimination significantly slower than arylidenecyclopropanes presence CuOAc (S,S)-Ph-BPE. The these two protocols further demonstrated through conducting various stereospecific site-selective transformations organoboron products, including concise synthesis bioactive molecules.

Language: Английский

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