First-Row d-Block Element-Catalyzed Carbon–Boron Bond Formation and Related Processes

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(21), P. 13238 - 13341

Published: Oct. 7, 2021

Organoboron reagents represent a unique class of compounds because their utility in modern synthetic organic chemistry, often affording unprecedented reactivity. The transformation the carbon–boron bond into carbon–X (X = C, N, and O) stereocontrolled fashion has become invaluable medicinal agrochemistry, natural products chemistry as well materials science. Over past decade, first-row d-block transition metals have increasingly widely used catalysts for formation bond, traditionally catalyzed by expensive precious metals. This recent focus on alternative enabled growth fundamental methods organoboron chemistry. review surveys current state-of-the-art use element-based bonds.

Language: Английский

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From C4 to C7: Innovative Strategies for Site-Selective Functionalization of Indole C–H Bonds

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(7), P. 1723 - 1736

Published: March 12, 2021

The widespread presence of hydrocarbons makes C-H functionalization an attractive alternative to traditional cross-coupling methods. As indole is important heteroarene in a plethora natural products and pharmaceuticals, moieties has emerged as one the most topics this field. Due multiple bonds indoles, site selectivity long-standing challenge. Much effort been devoted indoles at C3 or C2 position, while accessing benzene core (from C4 C7) considerably more challenging.This Account summarizes our recent efforts toward site-selective based on innovative strategies. A common method solve issue involves development directing groups (DGs). Our early studies establish that installation N-P(O)tBu2 group N position can produce C7 C6 arylation using palladium copper catalysts, respectively. developed system also be extended direct C5 positions by installing pivaloyl position. Further investigation bearing N-PtBu2 shows diverse reactivity for functionalizations including arylation, olefination, acylation, alkylation, silylation, carbonylation with different coupling partners. Compared P(V) DG, P(III) easily attached substrates detached from products. However, these reactions rely mostly precious metal catalysts ligands; requirement significant limitation, particularly large-scale syntheses necessity removal toxic trace metals pharmaceutical We have uncovered general strategy chelation-assisted aromatic borylation just simple BBr3 under mild conditions, which N1 selectively deliver boron species unfavorable allow subsequent without any metal. This transition-metal-free synthesize hydroxylated boron-mediated directed hydroxylation reaction conditions broad functional compatibility.In Account, we describe contributions topic since 2015. These provide efficient methods divergent synthesis valuable substituted insights into exploration new strategies directives other heteroarenes.

Language: Английский

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Site-selective C–H functionalization to access the arene backbone of indoles and quinolines

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(20), P. 11249 - 11269

Published: Jan. 1, 2021

The site-selective C-H bond functionalization of heteroarenes can eventually provide chemists with great techniques for editing and building complex molecular scaffolds. During the past decade, benzo-fused N-heterocycles such as indoles quinolines have been among most widely investigated organic templates. Early developments led to on pyrrole pyridine cores quinolines; however, benzenoid ring has remained a challenge in catalysis. In this review, we elaborate recent highly challenging bonds less-reactive core quinolines. These findings are mainly described selective directing group assisted strategies, remote their reaction mechanisms. underlying principle each strategy is elucidated, which aims facilitate design more advanced structure heterocycles based bioactive molecules, synthetic drugs, material aspects. Moreover, challenges perspectives catalytic access arene backbone also proposed conclusion section.

Language: Английский

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Tryptophan-specific modification and diversification of peptides and proteins

Organic & Biomolecular Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

This review provides an account of the tryptophan-specific conjugation peptides and proteins its extensive application in imaging living cells, radiolabelling proteins, protein engineering, etc .

Language: Английский

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Acyl‐Directed ortho‐Borylation of Anilines and C7 Borylation of Indoles using just BBr₃

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(43), P. 15381 - 15385

Published: Aug. 28, 2019

Indoles are privileged heterocycles found in many biologically active pharmaceuticals and natural products. However, the selective functionalization of benzenoid moiety indoles preference to more reactive pyrrolic unit is a significant challenge. Herein we report that N-acyl directing groups enable C7-selective C-H borylation using just BBr

Language: Английский

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C7‐Indole Amidations and Alkenylations by Ruthenium(II) Catalysis

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(30), P. 12534 - 12540

Published: June 2, 2020

C7-H-functionalized indoles are ubiquitous structural units of biological and pharmaceutical compounds for numerous antiviral agents against SARS-CoV or HIV-1. Thus, achieving site-selective functionalizations the C7-H position indoles, while discriminating among other bonds, is in high demand. Herein, we disclose activations by ruthenium(II) biscarboxylate catalysis under mild conditions. Base-assisted internal electrophilic-type substitution C-H ruthenation weak O-coordination enabled functionalization offered a broad scope, including C-N C-C bond formation. The versatile ruthenium-catalyzed were characterized gram-scale syntheses traceless removal directing group, thus providing easy access to pharmaceutically relevant scaffolds. Detailed mechanistic studies through spectroscopic spectrometric analyses shed light on unique nature robust ruthenium indoles.

Language: Английский

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Iridium‐Catalyzed Direct C4‐ and C7‐Selective Alkynylation of Indoles Using Sulfur‐Directing Groups

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(29), P. 9856 - 9860

Published: May 22, 2019

Abstract Indoles and their analogues have been one of the most ubiquitous heterocycles during past century, extensive studies conducted to establish practical synthetic methods for derivatives. In particular, selective functionalization poorly reactive benzenoid core over pyrrole ring has a great challenge. Reported herein is an iridium‐catalyzed direct alkynylation indole C4‐ C7‐positions with assistance sulfur directing groups. This transformation shows wide range functional‐group tolerance exceptional site selectivity. The group can be either easily removed or transformed after catalysis. utility alkyne fragment demonstrated by derivatization into structure natural alkaloids.

Language: Английский

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Aerobic Oxidative Functionalization of Indoles

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(18), P. 3795 - 3823

Published: May 18, 2020

Abstract The synthetic methodology for direct indole functionalizations is of great significance in chemistry and has been intensively investigated the last few decades. From perspective green chemistry, oxygen best choice as terminal oxidant molecular synthesis. Hence, aerobic oxidative functionalization indoles became a hot research topic decade. Numerous efficient protocols this field have discovered that enable facile transformations to related valuable compounds, which are summarized discussed detail review. magnified image

Language: Английский

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Peptide Late-Stage Diversifications by Rhodium-Catalyzed Tryptophan C7 Amidation

Chem, Journal Year: 2020, Volume and Issue: 6(12), P. 3428 - 3439

Published: Nov. 20, 2020

Language: Английский

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Recent Advances in the Catalytic Asymmetric Friedel–Crafts Reactions of Indoles

ACS Omega, Journal Year: 2022, Volume and Issue: 7(40), P. 35446 - 35485

Published: Oct. 3, 2022

Functionalized chiral indole derivatives are privileged and versatile organic frameworks encountered in numerous pharmaceutically active agents biologically natural products. The catalytic asymmetric Friedel–Crafts reaction of indoles, catalyzed by metal complexes or organocatalysts, is one the most powerful atom-economical approaches to access optically derivatives. Consequently, a wide range electrophilic partners including α,β-unsaturated ketones, esters, amides, imines, β,γ-unsaturated α-keto- α-ketiminoesters, ketimines, nitroalkenes, many others have been successfully employed achieve plethora functionalized moieties. In particular, strategies for C–H functionalization phenyl indoles require incorporation directing blocking group azole ring indole. discovery catalysts which can control enantiodiscrimination has gained great deal attention recent years. This review will provide an updated account on application synthesis diverse derivatives, covering timeframe from 2011 today.

Language: Английский

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