A Brief Introduction to Chemical Reaction Optimization

Chemical Reviews, Год журнала: 2023, Номер 123(6), С. 3089 - 3126

Опубликована: Фев. 23, 2023

From the start of a synthetic chemist's training, experiments are conducted based on recipes from textbooks and manuscripts that achieve clean reaction outcomes, allowing scientist to develop practical skills some chemical intuition. This procedure is often kept long into researcher's career, as new developed similar protocols, intuition-guided deviations through learning failed experiments. However, when attempting understand systems interest, it has been shown model-based, algorithm-based, miniaturized high-throughput techniques outperform human intuition optimization in much more time- material-efficient manner; this covered detail paper. As many chemists not exposed these undergraduate teaching, leads disproportionate number scientists wish optimize their reactions but unable use methodologies or simply unaware existence. review highlights basics, cutting-edge, modern well its relation process scale-up can thereby serve reference for inspired each techniques, detailing several respective applications.

Язык: Английский

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Recent advances in radical transformations of internal alkynes

Chemical Communications, Год журнала: 2018, Номер 54(77), С. 10791 - 10811

Опубликована: Янв. 1, 2018

Over the past years, impressive progress has been made on development of chemoselective and direct formation carbon-carbon carbon-heteroatom bonds involving internal alkynes under catalytic oxidative systems. These transformations heavily rely in situ generation reactive radical intermediates that are initiated by oxidants, visible light photocatalysis, or electrocatalysis so on. Numerous chemically biomedically important building blocks have synthesized, will continue to be obtained taking advantage transformation following years. In this review, we highlight recent rapidly growing area presenting a series reactions, mechanisms applications which appeared most literature.

Язык: Английский

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Desulfonylation via Radical Process: Recent Developments in Organic Synthesis

Chemical Reviews, Год журнала: 2021, Номер 121(20), С. 12548 - 12680

Опубликована: Авг. 13, 2021

As the "chemical chameleon", sulfonyl-containing compounds and their variants have been merged with various types of reactions for efficient construction diverse molecular architectures by taking advantage incredible reactive flexibility. Currently, involvement in radical transformations, which sulfonyl group typically acts as a leaving via selective C–S, N–S, O–S, S–S, Se–S bond cleavage/functionalization, has facilitated new formation strategies are complementary to classical two-electron cross-couplings organometallic or ionic intermediates. Considering great influence synthetic potential these novel avenues, we summarize recent advances this rapidly expanding area discussing reaction designs, substrate scopes, mechanistic studies, limitations, outlining state-of-the-art processes involved radical-mediated desulfonylation related transformations. With specific emphasis on applications, believe review will be useful medicinal organic chemists who interested chemistry particular.

Язык: Английский

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Modern Aspects of the Smiles Rearrangement

Chemistry - A European Journal, Год журнала: 2017, Номер 23(38), С. 8992 - 9008

Опубликована: Апрель 12, 2017

Abstract The Smiles rearrangement is an intramolecular S N Ar reaction, breaking a C−X single bond and forming new or C−C though ipso substitution. Its vast scope, in terms of nucleophile, leaving group, ring‐size the transition state, make it powerful tool for arene functionalization, as can be employed strategically to switch easily‐forged bonds with more difficult connections that would challenging realize intermolecular mode. reaction has received significantly renewed attention recent years, advances areas such formation radical generation have been harnessed syntheses through chemistry. In addition, modes discovered, Clayden lithiated ureas, creating innovative applications rearrangements asymmetric arylation. This Minireview will discuss these literature, covering both two‐electron, polar along single‐electron transformations.

Язык: Английский

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Ynamide Smiles Rearrangement Triggered by Visible-Light-Mediated Regioselective Ketyl–Ynamide Coupling: Rapid Access to Functionalized Indoles and Isoquinolines

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(7), С. 3636 - 3644

Опубликована: Янв. 31, 2020

In the past decades, significant advances have been made on radical Smiles rearrangement. However, eventually formed intermediates in these reactions are limited to amidyl radical, except for few examples initiated by a N-centered radical. Here, novel and practical rearrangement triggered photoredox-catalyzed regioselective ketyl-ynamide coupling is reported, which represents first of ynamides. This method enables facile access variety valuable 2-benzhydrylindoles with broad substrate scope generally good yields under mild reaction conditions. addition, this chemistry can also be extended divergent synthesis versatile 3-benzhydrylisoquinolines through similar rearrangement, followed dehydrogenative oxidation. Moreover, such an ynamide intermolecular photoredox catalysis via addition external sources achieved. By control experiments, was shown proceed key ketyl α-imino carbon intermediates.

Язык: Английский

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Aryl Transfer Strategies Mediated by Photoinduced Electron Transfer

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 2695 - 2751

Опубликована: Окт. 21, 2021

Radical aryl migrations are powerful techniques to forge new bonds in aromatic compounds. The growing popularity of photoredox catalysis has led an influx novel strategies initiate and control migration starting from widely available radical precursors. This review encapsulates progress enabled by photochemical methods─particularly catalysis─since 2015. Special attention is paid descriptions scope, mechanism, synthetic applications each method.

Язык: Английский

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Development of a Platform for Near-Infrared Photoredox Catalysis

ACS Central Science, Год журнала: 2020, Номер 6(11), С. 2053 - 2059

Опубликована: Окт. 20, 2020

Over the past decade, chemists have embraced visible-light photoredox catalysis due to its remarkable ability activate small molecules. Broadly, these methods employ metal complexes or organic dyes convert visible light into chemical energy. Unfortunately, excitation of widely utilized Ru and Ir chromophores is energetically wasteful as ∼25% energy lost thermally before being quenched productively. Hence, methodologies require high-energy, intense accommodate said catalytic inefficiency. Herein, we report photocatalysts which cleanly near-infrared (NIR) deep red (DR) with minimal energetic waste. We leverage strong spin-orbit coupling (SOC) Os(II) photosensitizers directly access excited triplet state (T1) NIR DR irradiation from ground singlet (S0). Through strategic catalyst design, a wide range photoredox, photopolymerization, metallaphotoredox reactions usually 15-50% higher Finally, demonstrate superior penetration scalability through mole-scale arene trifluoromethylation in batch reactor.

Язык: Английский

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Accessing chiral sulfones bearing quaternary carbon stereocenters via photoinduced radical sulfur dioxide insertion and Truce–Smiles rearrangement

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Ноя. 18, 2022

Abstract From the viewpoint of synthetic accessibility and functional group compatibility, photoredox-catalyzed sulfur dioxide insertion strategy enables in situ generation functionalized sulfonyl radicals from easily accessible starting materials under mild conditions, thereby conferring broader application potential. Here we present two complementary photoinduced systems to trigger radical asymmetric Truce–Smiles rearrangements for preparing a variety chiral sulfones that bear quaternary carbon stereocenter. This protocol features broad substrate scope excellent stereospecificity. Aside scalability, introduction stereocenter at position β bioactive molecule-derived further demonstrates practicality potential this methodology.

Язык: Английский

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Nickel-Catalyzed Reductive Cross-Coupling of Aryl Bromides with Alkyl Bromides: Et₃N as the Terminal Reductant

Organic Letters, Год журнала: 2016, Номер 18(16), С. 4012 - 4015

Опубликована: Июль 29, 2016

Reductive cross-coupling has emerged as a direct method for the construction of carbon–carbon bonds. Most cobalt-, nickel-, and palladium-catalyzed reductive reactions to date are limited stoichiometric Mn(0) or Zn(0) reductant. One nickel-catalyzed paradigm using Et3N terminal reductant is reported. By this photoredox catalysis nickel approach, Csp2–Csp3 aryl bromides with alkyl achieved under mild conditions without metal reductants.

Язык: Английский

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A Radical Smiles Rearrangement Promoted by Neutral Eosin Y as a Direct Hydrogen Atom Transfer Photocatalyst

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(26), С. 11357 - 11362

Опубликована: Июнь 16, 2020

A visible-light-mediated radical Smiles rearrangement has been achieved using neutral eosin Y as a direct hydrogen atom transfer (HAT) photocatalyst. Novel N-heterocycles single diastereomers featuring an isothiazolidin-3-one 1,1-dioxide moiety are directly accessed by this method. wide range of functional groups can be incorporated in the products employing diverse aldehydes and N-(hetero)arylsulfonyl propiolamides. The transformation proceeds through cascade visible-light-induced HAT, 1,4-addition, rearrangement, 5-endo-trig cyclization, reverse HAT process. Preliminary biological studies highly functionalized heterocyclic compounds suggest potential anticancer activity with some synthesized compounds.

Язык: Английский

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