Cooperative Catalyst‐Enabled Regio‐ and Stereodivergent Synthesis of α‐Quaternary α‐Amino Acids via Asymmetric Allylic Alkylation of Aldimine Esters with Racemic Allylic Alcohols DOI

Lu Xiao,

Xin Chang, Hui Xu

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(46)

Published: Sept. 26, 2022

We describe cooperative bimetallic catalysis that enables regio-/stereodivergent asymmetric α-allylations of aldimine esters. By employing Et3 B as the key activator, racemic allylic alcohols can be directly ionized to form Pd or Ir-π-allyl species in presence achiral chiral Ir complexes, respectively. The less more substituted termini metal-π-allyl are amenable nucleophilic attack by Cu-azomethine ylide, formation which is simultaneously facilitated B, affording α-quaternary α-amino acids with high regioselectivity and excellent stereoselectivity. use readily available electrophilic precursors represents an improvement from environmental atom/step economy perspective. Computational mechanistic studies reveal crucial role additive origins stereo- regioselectivities analyzing steric effects, dispersion interactions, frontier orbital population.

Language: Английский

Treatment strategies for cryptococcal infection: challenges, advances and future outlook DOI Open Access

Kali R. Iyer,

Nicole M. Revie,

Ci Fu

et al.

Nature Reviews Microbiology, Journal Year: 2021, Volume and Issue: 19(7), P. 454 - 466

Published: Feb. 8, 2021

Language: Английский

Citations

265

Challenges and Opportunities in Multicatalysis DOI
Sebastián Martínez, Lukas Veth,

Bruno Lainer

et al.

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(7), P. 3891 - 3915

Published: March 15, 2021

Multicatalysis is an emerging field targeting the development of efficient catalytic transformations to quickly convert relatively simple starting materials into more complex value-added products. Within multicatalytic processes either multiple catalysts execute single reactions or precise sequences occur in a "one-pot" fashion. Attractively, protocols not only enable that are inaccessible through classic approaches but also able significantly reduce time, waste, and cost synthetic processes, making organic synthesis resources efficient. In this Perspective article, we review different strategies multicatalysis bring distinct challenges opportunities. We divide overarching three main categories: cooperative, domino, relay catalysis. Each category described along with representative examples highlight its features. Special emphasis dedicated catalysis, which further discussed subcategories. Lastly, provide analysis systems incorporate higher levels complexity underscore potential systems.

Language: Английский

Citations

198

Stereodivergent Synthesis of Tertiary Fluoride-Tethered Allenes via Copper and Palladium Dual Catalysis DOI

Shao‐Qian Yang,

Yifan Wang,

Wei-Cheng Zhao

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(19), P. 7285 - 7291

Published: May 10, 2021

Herein we describe a protocol for the unprecedented stereodivergent synthesis of tertiary fluoride-tethered allenes bearing stereogenic center and axis via Cu/Pd synergistic catalysis. A broad scope conjugated enynes are coupled with various α-fluoroesters in high yields diastereoselectivities generally >99% ee. In addition, four stereoisomers allene products ensure precise access to corresponding fluorinated hydrofurans novel axial-to-central chirality transfer process.

Language: Английский

Citations

171

Enantio- and Diastereodivergent Construction of 1,3-Nonadjacent Stereocenters Bearing Axial and Central Chirality through Synergistic Pd/Cu Catalysis DOI
Jiacheng Zhang, Xiaohong Huo, Junzhe Xiao

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(32), P. 12622 - 12632

Published: Aug. 5, 2021

In contrast to the widely explored methods for asymmetric synthesis of molecules bearing a single stereocenter or adjacent stereocenters, concurrent construction 1,3-stereogenic centers in an enantio- and diastereoselective manner remains challenge, especially acyclic systems. Herein, we report diastereodivergent 1,3-nonadjacent stereocenters allenyl axial central chirality through synergistic Pd/Cu-catalyzed dynamic kinetic allenylation with racemic allenylic esters. The protocol is suitable wide range substrates including challenging esters less sterically bulky substituents provided chiral products high levels diastereoselectivities (up >20:1 dr >99% ee). Furthermore, several representative transformations involving axial-to-central transfer were conducted, affording useful structural motifs containing nonadjacent manner.

Language: Английский

Citations

166

Bimetallic Catalysis in Stereodivergent Synthesis DOI
Xiaohong Huo, Guanlin Li, Xi Wang

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(45)

Published: Aug. 2, 2022

Abstract Bimetallic catalysis has emerged as an efficient strategy for the development of new chemical reactions. Importantly, this also provides a simple and powerful platform stereodivergent synthesis, whereby all possible stereoisomers products bearing two stereocenters can be easily prepared from same set starting materials. In Minireview, allylic substitution, propargylic hydrofunctionalization, annulation based on bimetallic been summarized. It is expected that more catalytic systems will developed applied synthesis valuable molecules.

Language: Английский

Citations

143

Enantio‐ and Diastereodivergent Synthesis of Spirocycles through Dual‐Metal‐Catalyzed [3+2] Annulation of 2‐Vinyloxiranes with Nucleophilic Dipoles DOI

Youbin Peng,

Xiaohong Huo, Yicong Luo

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(47), P. 24941 - 24949

Published: Sept. 17, 2021

The development of efficient and straightforward methods for obtaining all optically active isomers structurally rigid spirocycles from readily available starting materials is great value in drug discovery chiral ligand development. However, the stereodivergent synthesis bearing multiple stereocenters remains an unsolved challenge owing to steric hindrance ring strain. Herein, we report enantio- diastereodivergent through dual-metal-catalyzed [3+2] annulation oxy π-allyl metallic dipoles with less commonly employed nucleophilic (imino esters). A series spiro compounds a pyrroline olefin were easily synthesized manner (up 19:1 dr, >99 % ee), which showed promise as new type N-olefin ligand. Preliminary mechanistic studies also carried out understand process this bimetallic catalysis.

Language: Английский

Citations

137

Streamlined Alkylation via Nickel-Hydride-Catalyzed Hydrocarbonation of Alkenes DOI
Zhikun Zhang, Srikrishna Bera, Chao Fan

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(16), P. 7015 - 7029

Published: April 12, 2022

Compounds rich in sp3-hybridized carbons are desirable drug discovery. Nickel-catalyzed hydrocarbonation of alkenes is a potentially efficient method to synthesize these compounds. By using abundant, readily available, and stable as pro-nucleophiles, reactions can have broad scope high functional group tolerance. However, this methodology still an early stage development, the first examples were reported only 2016. Herein, we summarize progress emerging field, with emphasis on enantioselective reactions. We highlight major developments, critically discuss wide range possible mechanisms, offer our perspective state challenges field. hope Perspective will stimulate future works area, making widely applicable organic synthesis.

Language: Английский

Citations

131

Stereodivergent Synthesis of Enantioenriched γ‐Butyrolactones Bearing Two Vicinal Stereocenters Enabled by Synergistic Copper and Iridium Catalysis DOI

Lu Xiao,

Liang Wei, Chun‐Jiang Wang

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(47), P. 24930 - 24940

Published: Oct. 11, 2021

By virtue of a fundamentally new reaction model azomethine ylide serving as two-atom synthon, we present the first example stereodivergent preparation γ-butyrolactones via synergistic Cu/Ir-catalyzed asymmetric cascade allylation/lactonization, and all four stereoisomers bearing two vicinal stereocenters are accessible with excellent diastereoselective enantioselective control. The chiral IrIII -π-allyl intermediate was separated characterized to understand origin regio- stereoselectivity initial C-C bond formation process. Control experiments shed some light on catalyst/substrate catalyst/catalyst interactions in this dual catalytic system rationalize related kinetic/dynamic kinetic resolution process different catalyst combinations. enantioenriched γ-butyrolactone products were converted into an array structurally complex molecules organocatalysts that otherwise inaccessible.

Language: Английский

Citations

115

Dispersion and Steric Effects on Enantio-/Diastereoselectivities in Synergistic Dual Transition-Metal Catalysis DOI
Bo Li, Hui Xu, Yanfeng Dang

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(4), P. 1971 - 1985

Published: Jan. 20, 2022

Comprehensive computational studies were carried out to explore the mechanisms of enantioselective Cu/Pd and stereodivergent Cu/Ir dual-catalytic syntheses α,α-disubstituted α-amino acids (α-AAs). A chiral copper azomethine ylide undergoes facile α-allylation with racemic π-allylpalladium species or stereopure π-allyliridium complex stereoconvergently stereodivergently furnish single/double stereocenters, respectively. Stereoselectivity at α-center is controlled by facial selectivity respect prochiral nucleophile. Despite apparently similar transition-state assemblies, models distortion/interaction analyses disclose versatile modes stereoinduction wherein can face-selectively intercept metal−π-allyl intermediates utilizing attractive dispersion interactions and/or sterically caused distortions. Generation β-stereocenter in system relies on a stereospecifically generated allyliridium electronically branched-to-linear selectivity, while dual yields linear monochiral product due steric factors π–π stacking interactions. The demonstrate molecular level how ligand-encoded information transferred α-/β-sites resulting α-AAs mode regio-/stereoselection altered differences transition-metal-stabilized coupling partners. To facilitate stereoselective catalysis, suite analytical tools extract controlling for asymmetric induction demonstrated.

Language: Английский

Citations

111

Multifunctional carbon nitride nanoarchitectures for catalysis DOI
Prashant Kumar, Gurwinder Singh, Xinwei Guan

et al.

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(21), P. 7602 - 7664

Published: Jan. 1, 2023

Carbon nitrides, with feasibility of tailored band gap via suitable nanoarchitectonics, are deemed as best catalysts amongst existing materials, especially for HER, OWS, COR, NRR, water oxidation, pollutant removal, and organocatalysis.

Language: Английский

Citations

101