Eu(OTf)₃‐Catalyzed Formal Dipolar [4π+2σ] Cycloaddition of Bicyclo‐[1.1.0]butanes with Nitrones: Access to Polysubstituted 2‐Oxa‐3‐azabicyclo[3.1.1]heptanes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(13)

Published: Jan. 30, 2024

Abstract Herein, we have synthesized multifunctionalized 2‐oxa‐3‐azabicyclo[3.1.1]heptanes, which are considered potential bioisosteres for meta ‐substituted arenes, through Eu(OTf) 3 ‐catalyzed formal dipolar [4π+2σ] cycloaddition of bicyclo[1.1.0]butanes with nitrones. This methodology represents the initial instance fabricating bicyclo[3.1.1]heptanes adorned multiple heteroatoms. The protocol exhibits both mild reaction conditions and a good tolerance various functional groups. Computational density theory calculations support that mechanism likely involves nucleophilic addition nitrones to bicyclo[1.1.0]butanes, succeeded by an intramolecular cyclization. synthetic utility this novel has been demonstrated in concise synthesis analogue Rupatadine.

Language: Английский

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Iridium-Catalyzed Asymmetric Difunctionalization of C–C σ-Bonds Enabled by Ring-Strained Boronate Complexes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(30), P. 16508 - 16516

Published: July 20, 2023

Enantioenriched organoboron intermediates are important building blocks in organic synthesis and drug discovery. Recently, transition metal-catalyzed enantioselective 1,2-metalate rearrangements of alkenylboronates have emerged as an attractive protocol to access these valuable reagents by installing two different carbon fragments across C═C π-bonds. Herein, we report the development iridium-catalyzed asymmetric allylation-induced rearrangement bicyclo[1.1.0]butyl (BCB) boronate complexes enabled strain release, which allows difunctionalization C-C σ-bonds, including dicarbonation carboboration. This provides a variety enantioenriched three-dimensional 1,1,3-trisubstituted cyclobutane products bearing boronic ester that can be readily derivatized. Notably, reaction gives trans diastereoisomers result from anti-addition σ-bond, is contrast syn-additions observed for reactions promoted PdII-aryl other electrophiles our previous works. The diastereoselectivity has been rationalized based on combination experimental data density functional theory calculations, suggest BCB highly nucleophilic react via early states with low activation barriers.

Language: Английский

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Advances in Catalytic Asymmetric Reactions Involving o-Hydroxybenzyl Alcohols

Chinese Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 43(3), P. 974 - 974

Published: Jan. 1, 2023

a 江苏师范大学化学与材料科学学院 江苏徐州 221116

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Ir‐Catalyzed Enantioselective Synthesis of gem‐Diborylalkenes Enabled by 1,2‐Boron Shift

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(32)

Published: June 15, 2023

Abstract Asymmetric cross‐couplings based on 1,2‐carbon migration from B‐ate complexes have been developed efficiently to access valuable organoboronates. However, enantioselective reactions triggered by 1,2‐boron shift remained be unaddressed synthetic challenge. Here, Ir‐catalyzed asymmetric allylic alkylation enabled was developed. In this reaction, we disclosed that excellent enantioselectivities were achieved through an interesting dynamic kinetic resolution (DKR) process of carbonates at the elevated temperature. Notably, highly (bis‐boryl)alkenes array diversifications versatile molecules. Extensive experimental and computational studies conducted elucidate reaction mechanism DKR clarify origin enantioselectivities.

Language: Английский

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Synthesis of Chiral Heterocycles Through Enantioselective Silver‐Catalyzed Transformations

European Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 2, 2025

Abstract This review collects the recent developments in synthesis of chiral heterocycles through enantioselective silver‐catalyzed transformations published since 2018. It demonstrates power silver catalysts as special mild Lewis acids to provide an impressive diversity reaction pathways, such 1,3‐dipolar cycloadditions, various types cyclizations, along with a wide variety more complex domino/tandem reactions, allowing many novel heterocyclic products be achieved high enantioselectivities.

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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Exploiting the reactivities ofortho-alkynyl aryl ketones: opportunities in designing catalytic annulation reactions

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 10(2), P. 570 - 589

Published: Dec. 10, 2022

We provide a comprehensive overview of recent progress in this rapidly growing field by summarizing catalytic annulation reactions ortho -alkynyl aryl ketones which involve carbo- and oxo -cyclization patterns with consideration their mechanisms applications.

Language: Английский

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Iridium-Catalyzed Diastereo- and Enantioselective [4 + 1] Cycloaddition of Hydroxyallyl Anilines with Sulfoxonium Ylides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(25), P. 4621 - 4626

Published: June 15, 2023

We present here an iridium-catalyzed diastereo- and enantioselective [4 + 1] cycloaddition reaction of hydroxyallyl anilines with sulfoxonium ylides under mild conditions, leading to 3-vinyl indolines in moderate good yields excellent enantioselectivities. Control experiments disclosed a plausible mechanism.

Language: Английский

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Ir-Catalyzed Asymmetric Cascade Allylation/Spiroketalization Reaction for Stereoselective Synthesis of Oxazoline-Spiroketals

Organic Letters, Journal Year: 2023, Volume and Issue: 25(2), P. 325 - 330

Published: Jan. 6, 2023

An asymmetric cascade allylation/spiroketalization reaction between 2-(1-hydroxyallyl)phenols and 5-methyleneoxazolines is accomplished by using a chiral Ir(I) catalyst derived from commercially available iridium precursor the Carreira ligand. This protocol furnishes class of structurally novel unique oxazoline-spiroketals in up to 86% yield, >99% ee >20:1 dr. Moreover, control experiments reveal that 4,4-disubstitution on necessary avoid aromatization for spiroketalization occur. On basis this, plausible mechanism illustrated.

Language: Английский

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Enantioconvergent and diastereoselective synthesis of atropisomeric hydrazides bearing a cyclic quaternary stereocenter through ternary catalysis

Chemical Science, Journal Year: 2024, Volume and Issue: 15(33), P. 13240 - 13249

Published: Jan. 1, 2024

The enantioselective and diastereoselective synthesis of atropisomeric hydrazides with defined vicinal central axial chirality via ternary catalysis in a one-pot process is reported.

Language: Английский

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