Reactions of organoboron compounds enabled by catalyst-promoted metalate shifts

Chemical Society Reviews, Journal Year: 2019, Volume and Issue: 48(13), P. 3464 - 3474

Published: Jan. 1, 2019

This tutorial review describes recent developments in catalytic reaction design that involve catalyst-promoted 1,2-metalate shifts as a critical part of the mechanism.

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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Sequential and direct multicomponent reaction (MCR)-based dearomatization strategies

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 49(23), P. 8721 - 8748

Published: Jan. 1, 2020

This review focuses on the comprehensive understanding of different multicomponent reaction (MCR) cascades involving dearomatization as characteristic step.

Language: Английский

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Stereospecific 1,2‐Migrations of Boronate Complexes Induced by Electrophiles

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(39), P. 16859 - 16872

Published: June 27, 2020

The stereospecific 1,2-migration of boronate complexes is one the most representative reactions in boron chemistry. This process has been used extensively to develop powerful methods for asymmetric synthesis, with applications spanning from pharmaceuticals natural products. Typically, driven by displacement an α-leaving group, oxidation α-boryl radical, or electrophilic activation alkenyl complex. aim this article summarize recent advances rapidly expanding field electrophile-induced groups sp

Language: Английский

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An Olefinic 1,2‐Boryl‐Migration Enabled by Radical Addition: Construction ofgem‐Bis(boryl)alkanes

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(28), P. 9448 - 9452

Published: May 6, 2019

A series of in situ formed alkenyl diboronate complexes from Grignard reagents (commercially available or prepared bromides and Mg) with B2 Pin2 (bis(pinacolato)diboron) react diverse alkyl halides by a Ru photocatalyst to give various gem-bis(boryl)alkanes. Alkyl radicals add efficiently the complexes, adduct radical anions undergo radical-polar crossover, specifically, 1,2-boryl-anion shift boron α-carbon sp2 center. This transformation shows good functional-group compatibility can serve as powerful synthetic tool for late-stage functionalization complex compounds. Measurements quantum yield reveal that radical-chain mechanism is operative which diboronates acts reductive quencher excited state photocatalyst.

Language: Английский

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Enantioselective, Lewis Base-Catalyzed Carbosulfenylation of Alkenylboronates by 1,2-Boronate Migration

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(46), P. 15621 - 15625

Published: Nov. 9, 2018

A catalytic, enantioselective method for the preparation of chiral, non-racemic, alkylboronic esters bearing two vicinal stereogenic centers is described. The reaction proceeds via a 1,2-migration zwitterionic thiiranium–boronate complex to give exclusively anti carbosulfenylation products. broad scope aryl groups migrate with good yield and excellent enantioselectivity (up 99:1 e.r.). Similarly, range di- trisubstituted alkenylboronic are competent partners. This provides access both secondary tertiary chiral esters.

Language: Английский

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Enantioselective Allylation of Alkenyl Boronates Promotes a 1,2-Metalate Rearrangement with 1,3-Diastereocontrol

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(13), P. 4921 - 4927

Published: March 23, 2021

Alkenyl boronates add to Ir(π-allyl) intermediates with high enantioselectivity. A 1,2-metalate shift forms a second C–C bond and sets 1,3-stereochemical relationship. The three-component coupling provides tertiary boronic esters that can undergo multiple additional functionalizations. An extension trisubstituted olefins three contiguous stereocenters.

Language: Английский

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Uncovering the Potential of Boronic Acid and Derivatives as Radical Source in Photo(electro)chemical Reactions

Advanced Synthesis & Catalysis, Journal Year: 2022, Volume and Issue: 364(10), P. 1643 - 1665

Published: April 25, 2022

Abstract The chemistry of boron compounds has been profoundly investigated in the last decades, leading to ubiquity many synthetic applications as well biologically active molecules. Since advent photoredox catalysis, an upsurge discovery suitable radical precursors witnessed, and is becoming a protagonist this field. Despite studies focused on trifluoroborates, use boronic acids esters have received much less attention regard. Because their high oxidation potential, development methods enable involvement photocatalyzed reactions only recent. Nonetheless, review summarizes novel strategies developed unlock role photochemical discloses potential that own, when intrinsic chemical properties are exploited. magnified image

Language: Английский

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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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Alkyl Radical Generation from Alkylboronic Pinacol Esters through Substitution with Aminyl Radicals

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(16), P. 8770 - 8775

Published: April 14, 2023

Alkylboronic pinacol esters (APEs) are highly versatile reagents in organic synthesis. However, the direct generation of alkyl radicals from commonly used, bench-stable APEs has not been well explored. In this communication, radical through reaction with aminyl is reported. The readily generated by visible-light-induced homolytic cleavage N-N bond N-nitrosamines, and C occurs nucleohomolytic substitution at boron. As an application, efficient photochemical alkyloximation alkenes N-nitrosamines under mild conditions presented. A wide range primary, secondary, tertiary engage transformation that easily scaled up.

Language: Английский

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