Recent Progress toward the Construction of Axially Chiral Molecules Catalyzed by an N-heterocyclic Carbene

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(20), P. 12520 - 12531

Published: Sept. 28, 2021

Axial chirality widely exists in natural products, pharmaceutical compounds, and other functional molecules; these axially chiral compounds also find wide utility as catalysts or ligands organic synthetic chemistry. Nevertheless, whereas significant progress has been made toward the synthesis of enantioenriched molecules over past two decades, strategies involving organocatalysis have only started to emerge recently. N-heterocyclic carbene (NHC) organocatalysts recognized be powerful tools for rapid construction complex molecular architectures. However, previous works mainly focused on assembly point recently it realized that asymmetric axial could achieved by using NHCs organocatalysts. This Perspective highlights developments advances scaffolds catalyzed NHCs. The aim this is provide an overview area serve a stepping stone future investigations.

Language: Английский

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Enantioselective C–H Functionalization toward Silicon-Stereogenic Silanes

Synthesis, Journal Year: 2022, Volume and Issue: 54(08), P. 1939 - 1950

Published: Jan. 3, 2022

Abstract In recent years, transition-metal-catalyzed enantioselective C–H bond functionalization has emerged as a powerful and attractive synthetic approach to access silicon-stereogenic centers, which provides impetus for the innovation of chiral organosilicon chemistry. This short review summarizes advances in construction silanes via functionalization. We endeavor highlight great potential this methodology hope that will shed light on new perspectives inspire further research emerging area. 1 Introduction 2 Enantioselective Functionalization Induced by Oxidative Addition­ an Aryl-OTf Bond 3 Silacyclobutane 4 Directing-Group-Assisted 5 Dehydrogenative C–H/Si–H Coupling 5.1 C(sp2)–H Silylation 5.2 C(sp3)–H 6 Summary Outlook

Language: Английский

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Catalytic Asymmetric Synthesis of Atropisomers Bearing Multiple Chiral Elements: An Emerging Field

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(3)

Published: Nov. 2, 2023

With the rapid development of asymmetric catalysis, demand for enantioselective synthesis complex and diverse molecules with different chiral elements is increasing. Owing to unique features atropisomerism, catalytic atropisomers has attracted a considerable interest from chemical science community. In particular, introducing additional elements, such as carbon centered chirality, heteroatomic planar helical into provides an opportunity incorporate new properties axially compounds, thus expanding potential applications atropisomers. Thus, it important perform transformations synthesize bearing multiple elements. spite challenges in transformations, recent years, chemists have devised powerful strategies under organocatalysis or metal synthesizing wide range enantioenriched Therefore, become emerging field. This review summarizes progress this field indicates challenges, thereby promoting horizon.

Language: Английский

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Organocatalytic Enantioselective Construction of Chiral Azepine Skeleton Bearing Multiple‐Stereogenic Elements

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(39), P. 21486 - 21493

Published: July 8, 2021

Abstract Enantioselective construction of molecules bearing multiple stereogenic elements is increasingly related to the synthesis enantiopure natural products, pharmaceuticals, and functional materials. However, atom‐economical enantioselective approaches install in a small molecular template by limited chemical transformation remain challenging. We describe an organocatalytic method for preparation polychiral four types fused azepines via vinylidene ortho ‐quinone methide ( VQM )‐mediated intramolecular electrophilic aromatic substitution. This was proved robust with wide range substrate scope (46–92 % yield), excellent diastereoselectivity (>20:1 dr) enantioselectivity achieved (up 97 ee ). Optical properties Ru 3+ ‐induced fluorescence responses these compounds suggest their potential applications optoelectronic materials heavy metal ion detection.

Language: Английский

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Construction of Si‐Stereogenic Silanes through C−H Activation Approach

European Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 2021(44), P. 6006 - 6014

Published: Sept. 21, 2021

Abstract The asymmetric synthesis of Si‐stereogenic silanes has attracted great attention due to the increasing values Si‐containing functional molecules in synthetic chemistry, medicinal and material chemistry. Merging organosilicon chemistry with transition‐metal‐catalyzed C−H approach led rich sets new reactions holding values. This Minireview aims summarize advances construction through activation approach.

Language: Английский

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Catalytic Enantioselective Construction of Chiroptical Boron-Stereogenic Compounds

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(39), P. 16302 - 16310

Published: Sept. 27, 2021

The construction of main group heteroatom-stereogenic compounds is great importance due to their intriguing chemical, physical, biological, and stereoelectronic properties. Despite that organoboron are widely used in organic chemistry, the creation a tetrahedral boron-stereogenic center one enantiomeric form remains highly challenging. Given labile nature ligands attached tetracoordinate boron atom, only handful enantioenriched have been reported via resolution or chiral substrate-induced diastereoselective approach. To date catalytic asymmetric synthesis has remained unknown. Here, we demonstrate first enantioselective an copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. This CuAAC reaction not gives access wide range novel functionalized heterocycles high yields with good excellent enantioselectivities but also produces optically active terminal alkyne triazole moieties various potential application prospects. Further transformation delivers several complex heterocyclic entities bearing centers without loss enantiopurity. Moreover, X-ray structure, barrier racemization, HOMO/LUMO gap selected investigated. Notably, these N,N π-conjugated exhibit bright fluorescence. optical properties, including circular dichroism, quantum yield, polarized luminescence spectroscopies, examined. These features expand chemical space chiroptical boron-based dye platform, which could applications optoelectronic materials.

Language: Английский

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Nickel(0)-catalyzed divergent reactions of silacyclobutanes with internal alkynes

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: June 13, 2022

Abstract Transition metal-catalyzed reactions of silacyclobutanes with a variety π units have attracted much attention and become one the most straightforward efficient approaches to rapidly access structurally diverse organosilicon compounds. However, reaction alkynes still suffers from some limitations: (1) internal remain challenging substrates; (2) expensive Pd- or Rh-based catalysts been employed in all existing systems; (3) controlling chemodivergence has not yet realized. Herein we realize Ni-catalyzed chemodivergent alkynes. In comparison previous Pd Rh catalytic systems, our Ni-catalytic system features: 1) complementary substrate scope; 2) ligand-controlled chemodivergence; 3) low cost. The ligand precisely dictates pathway selectivity, leading divergent formation (benzo)silacyclohexenes allyl vinylsilanes. Moreover, demonstrate that employment chiral phosphine is capable forming silicon-stereogenic vinylsilanes high yields enantioselectivities. addition, DFT calculation performed elucidate origin switchable selectivities, which mainly attributed different steric effects.

Language: Английский

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Synthesis of Silicon-Stereogenic Silanols Involving Iridium-Catalyzed Enantioselective C–H Silylation Leading to a New Ligand Scaffold

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(17), P. 10748 - 10753

Published: Aug. 13, 2021

Despite a growing focus on the construction of highly enantioenriched silicon-stereogenic organosilicon compounds, enantioselective synthesis silanols through asymmetric catalysis remains considerable challenge. Herein, we realized diarylsilanols via an Ir-catalyzed C–H silylation along with stereospecific substitution or Tamao–Fleming oxidation. This strategy gives rise to class chiral diol catalyst cores (PSiOLs). Transformation PSiOLs led ligand possessing both Si and P-stereocenters, which is capable inducing excellent enantioselectivity in rhodium(I)-catalyzed conjugate 1,4-addition aryl boronic acids cyclohexenone.

Language: Английский

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Organocatalytic Asymmetric Synthesis of Si-Stereogenic Silyl Ethers

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(23), P. 10156 - 10161

Published: June 1, 2022

Functionalized enantiopure organosilanes are important building blocks with applications in various fields of chemistry; nevertheless, asymmetric synthetic methods for their preparation rare. Here we report the first organocatalytic enantioselective synthesis tertiary silyl ethers possessing "central chirality" on silicon. The reaction proceeds via a desymmetrizing carbon-carbon bond forming silicon-hydrogen exchange symmetrical bis(methallyl)silanes phenols using newly developed imidodiphosphorimidate (IDPi) catalysts. A variety was obtained high yields good chemo- and enantioselectivities could be readily derivatized to several useful chiral silicon compounds, leveraging olefin functionality leaving group nature phenoxy substituent.

Language: Английский

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Rhodium‐Catalyzed Dynamic Kinetic Asymmetric Hydrosilylation to Access Silicon‐Stereogenic Center

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(51)

Published: Nov. 4, 2022

Abstract Strategies on the construction of enantiomerically pure silicon‐stereogenic silanes generally relies desymmetrization prochiral and symmetric substrates. However, dynamic kinetic asymmetric transformations organosilicon compounds have remained underdeveloped unforeseen owing to a lack an effective method for deracemization static silicon stereocenters. Here we report first Rh‐catalyzed intramolecular hydrosilylation (DyKAH) with “silicon‐centered” racemic hydrosilanes that enables facile preparation benzosiloles in good yields excellent enantioselectivities. The special rhodium catalyst controlled by non‐diastereopure‐type mixed phosphine‐phosphoramidite ligand axial chirality multiple stereocenters can induce enantioselectivity efficiently this novel DyKAH reaction. Density functional theory (DFT) calculations suggest amide moiety chiral plays important role facilitating S N 2 substitution chloride ion realize inversion center.

Language: Английский

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