Small-Molecule-Based Strategy for Mitigating Deactivation of Chiral Lewis Acid Catalysis DOI

Fangqiu Lu,

Taku Kitanosono, Yasuhiro Yamashita

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(33), P. 22918 - 22922

Published: Aug. 6, 2024

Chiral Lewis acid catalysts are widely used in organic synthesis due to their diverse applications. However, high acidity makes them susceptible deactivation by basic reagents and water. Here, we present a novel strategy for mitigating this using small molecules. By incorporating weakly coordinating anions into the secondary coordination sphere of metal center, designed highly reusable chiral complex. This complex exhibits excellent thermal stability allows use electron-poor nucleophiles reactions. Spectroscopic titration studies confirmed robustness optimized work provides valuable insights overcoming limitations acids environments, expanding potential chemical synthesis.

Language: Английский

Asymmetric Three-Component Radical Alkene Carboazidation by Direct Activation of Aliphatic C–H Bonds DOI
Liang Ge,

Hongkai Wang,

Yangbin Liu

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(19), P. 13347 - 13355

Published: May 6, 2024

Azide compounds are widely present in natural products and drug molecules, their easy-to-transform characteristics make them used the field of organic synthesis. The merging transition-metal catalysis with radical chemistry offers a versatile platform for carboazidation alkenes, allowing rapid assembly highly functionalized azides. However, direct use readily available hydrocarbon feedstocks as sp

Language: Английский

Citations

16
Iron-Catalyzed Asymmetric Imidation of Sulfides via Sterically Biased Nitrene Transfer DOI
Zhenzhong Liu, Hongli Wu,

H Huiqi Zhang

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(26), P. 18050 - 18060

Published: June 15, 2024

Transition-metal-catalyzed enantioselective nitrene transfer to sulfides has emerged as one of the most powerful strategies for rapid construction enantioenriched sulfimides. However, achieving stereocontrol over highly active earth-abundant transition-metal nitrenoid intermediates remains a formidable challenge compared with precious metals. Herein, we disclose chiral iron(II)/N,N′-dioxide-catalyzed imidation dialkyl and alkyl aryl using iminoiodinanes precursors. A series sulfimides were obtained in moderate-to-good yields high enantioselectivities (56 examples, up 99% yield, 98:2 e.r.). The utility this methodology was demonstrated by late-stage modification complex molecules synthesis insecticide sulfoxaflor related bioactive compounds. Based on experimental studies theoretical calculations, water-bonded high-spin iron species identified key intermediate. observed stereoselectivity original from steric repulsion between amide unit ligand cave bulky substituent sulfides. Additionally, dioxazolones proved be suitable acylnitrene precursors presence an iron(III)/N,N′-dioxide complex, resulting formation enantioselectivity-reversed (14 81% 97:3

Language: Английский

Citations

11
Stereodivergent conjugate reduction of α-substituted α,β-unsaturated N-sulfinyl ketimines: flexible access to challenging acyclic β,β-disubstituted enesulfinamides DOI
Nuermaimaiti Yisimayili, Tao Liu,

Teng-Zhao Xiong

et al.

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(4), P. 1218 - 1224

Published: Jan. 1, 2024

Stereodivergent 1,4-reduction to provide flexible access the challenging acyclic enesulfinamides featuring two electronically and sterically similar β-substituents.

Language: Английский

Citations

10
Quinone-Initiated Photocatalytic Enantioselective Giese Radical Addition with Ethers, Thioethers, Amines, and Alkanes DOI
Yao Luo, Yuqiao Zhou,

Fengnan Xiao

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(16), P. 12031 - 12041

Published: July 29, 2024

Photocatalytic enantioselective Giese radical addition with inert C(sp3)–H bonds represents a highly efficient and economically favorable approach to synthesizing diverse value-added chiral molecules from abundant feedstock. Herein, we disclose quinone-initiated photocatalytic asymmetric of α-substituted acrylamides by applying simple quinones as HAT photocatalysts in combination N,N′-dioxide/praseodymium(III) catalyst. A wide array ethers, thioethers, selenide, amines, alkanes can smoothly transform into the corresponding α-aryl amide derivatives satisfactory enantioselectivities (68 examples, up 95% ee) under mild conditions. Based on spectroscopy studies control experiments, catalytic cycle was proposed, DFT calculations revealed that interaction between quinone Lewis acid essential for enantio-induction back hydrogen atom transfer process.

Language: Английский

Citations

6
Solvent-Regulated Cyclization of Arylidene Isoxazolones with Amidines for Regiodivergent Synthesis of 4- and 5-Acylimidazoles DOI
Siqi Chen, Mingjun Li, Yi Wu

et al.

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 27, 2025

N-Iodosuccinimide-promoted cascade reactions of arylidene isoxazolones with amidines in p-xylene were accomplished, affording 5-acylimidazoles good to excellent yields. Interestingly, when the performed by employing acetonitrile as solvent, 4-acylimidazoles efficiently obtained. Mechanistic studies indicate that formation imidazolyl and acyl moieties may undergo a spiroannulation-ring opening aromatization-hydrolysis reaction sequence. Based on this solvent-regulated tandem strategy, powerful protocol for switchable regiodivergent synthesis structurally diverse was successfully established.

Language: Английский

Citations

0
Chiral Supramolecular Self-Assembly Catalysts with Enhanced Metal Ion Interaction for Higher Enantioselectivity DOI

Cong Gao,

Yemeng Sun,

Zhengjie Miao

et al.

Langmuir, Journal Year: 2024, Volume and Issue: 40(28), P. 14555 - 14560

Published: June 28, 2024

Understanding the interaction between metal ions as catalytic centers and supramolecular scaffolds chiral substrates plays an important role in developing catalysts with high enantioselectivity. Herein, we found that compared l-norleucine amphiphile (l-NorC16), l-methionine (l-MetC16) only heteroatom of S site difference hydrophilic group can form a similar nanoribbon (NR) bilayer structure through self-assembly approach; yet, Cu(II) ion is reinforced, favoring chirality transfer therefore enhancing their enantioselectivity Diels–Alder reaction from 23% [l-NorC16-NR-Cu(II)] to 78% [l-MetC16-NR-Cu(II)]. Our work demonstrates new strategy perspective strengthening ion–supramolecular scaffold for preparation good

Language: Английский

Citations

3
Tandem catalytic allylic C–H amination and asymmetric [2,3]-rearrangement via bimetallic relay catalysis DOI Creative Commons
Zhenwei Wu, Xi Yang, Fangqing Zhang

et al.

Chemical Science, Journal Year: 2024, Volume and Issue: 15(33), P. 13299 - 13305

Published: Jan. 1, 2024

An asymmetric tandem allylic C–H amination and [2,3]-sigmatropic rearrangement has been developed by making use of bimetallic relay catalysis with an achiral Pd(0) catalyst a chiral N,N ′-dioxide-Mg( ii ) complex.

Language: Английский

Citations

3
Asymmetric Synthesis of Hydrodibenzofurans from Norcaradienes: Kinetic Resolution via [3 + 2] Cycloaddition with Quinones DOI
Siyuan Wang, Lichao Ning, Zhiqiang Li

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(18), P. 3844 - 3849

Published: April 25, 2024

The catalytic asymmetric [3 + 2] cycloaddition of racemic norcaradienes with quinones to construct multicyclic hydrodibenzofurans was achieved by the use chiral N,N′-dioxide/metal complex catalysts. Kinetic resolution accompanied partial racemization occurred, and one enantiomer in prior acted as C2 synthon participate diastereoselective cycloaddition. An enantiodivergent synthesis via a switch metal ions observed when naphthoquinone used partner. DFT calculations revealed profiles processes.

Language: Английский

Citations

2
Copper-catalyzed asymmetric dearomatizing amination of 2-naphthols: Csp2–N coupling via 1,3-reductive elimination DOI

Aying Yihuo,

Maoping Pu, Zheng Tan

et al.

Science China Chemistry, Journal Year: 2024, Volume and Issue: 67(8), P. 2694 - 2700

Published: July 2, 2024

Language: Английский

Citations

2
Asymmetric Clicking of Alkynyl Dipolarophiles and Nitrones Catalyzed by a Well-Defined Chiral Iron Complex DOI
Zhen‐Ni Zhao, Fengkai He, Yuhao Wang

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(17), P. 13291 - 13302

Published: Aug. 21, 2024

The enantioselective 1,3-dipolar cycloaddition of alkynes and α-aliphatic nitrones has long been recognized as an important challenge, while considerable progress made for the alkenes aromatic nitrones. We herein report example earth-abundant iron-catalyzed click-approach nonterminal alkynyl imides nitrones, highly functionalized chiral 4-isoxazolines having a 3-alkyl-substituted stereogenic carbon center are modularly generated in up to >99% yield 98% ee (54 examples). Although steric bulk substituent on nitrone plays key role achieving effective enantiocontrol, challenge bias differentiation between linear alkyl chain (Me, Et, etc.) H is also successfully overcome. enantioface discrimination presumably rooted well-defined octahedral mononuclear ferrous complex containing dual tridentate ligands (L*·Fe(OTf)2·L*, L* = (R,R)-DBFOX-Ph) possible dual-mode σ,π-binding activation, which evidenced by ESI-HRMS single crystal X-ray analysis, well L*/Fe ratio effect DFT calculations. Arguably, most interesting aspect that iron can induce superpositive nonlinear bisoxazoline ligand with low enantiopurity 22% results 84% cycloadduct. Practicability utility demonstrated gram-scale synthesis ready downstream functionalization based 4-isoxazoline core imide functional group.

Language: Английский

Citations

2