Recent Advances in Visible Light-Induced C-H Functionalization of Imidazo[1,2-a]pyridines

Molecules, Journal Year: 2025, Volume and Issue: 30(3), P. 607 - 607

Published: Jan. 30, 2025

The imidazo[1,2-a]pyridine skeleton is widely present in many natural products and pharmaceutical agents. Due to its impressive significant biological activities, such as analgesic, anti-tumor, antiosteoporosis, anxiolytic properties, the derivatization of has attracted widespread attention from chemists. In recent years, progress been made imidazo[1,2-a]pyridines through direct C-H functionalization, especially visible light induction. This review highlights advances light-induced functionalization during past ten some reaction mechanisms are also discussed.

Language: Английский

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Fluoroalkyl Iodides in Fluoroalkylative Difunctionalization of C−C Multiple Bonds

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(13), P. 2092 - 2125

Published: May 16, 2023

Abstract Fluorinated alkyl iodides serve as a convenient and inexpensive source of fluoroalkyl radicals that can readily undergo addition to the C−C unsaturated bonds alkynes alkenes which is foundation for variety useful synthetic protocols. Since 2010 this field has witnessed huge progress in several respects. First portfolio fluorinated was extended beyond only simple perfluoroalkyl (C n F 2n+1 I). In particular, employment iododifluoro−methyl‐ carbonyls phosphonates enabled facile installation medicinally relevant difluoromethylene motif. Secondly, from conceptual point view, novel strategies activation towards radical formation have been introduced, relying on electron donor‐acceptor (EDA) complexes, photoredox catalysis, frustrated Lewis pairs transition metal complementing prior approaches based heat UV induced C−I homolysis, initiators, transfer processes. Based these range fluoroalkylative transformations systems added classical iodoperfluoroalkylation. Broadly applicable protocols fluoroalkylation hydrofluoroalkylation, well more sophisticated, complexity‐building methods fluoroalkylation‐annulation tandem multicomponent fluoroalkylations with concomitant another functionality recently disclosed. This review summarizes achieved since reactivity emphasis placed above‐mentioned advances.

Language: Английский

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Harnessing photocatalytic and electrochemical approaches for C–H bond trifluoromethylation and fluoroalkylation

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 11(3), P. 954 - 1014

Published: Dec. 14, 2023

The review summarises various photo- and electrochemical strategies for trifluoromethylation fluoroalkylation of different C(sp 3 )–H, 2 C(sp)–H bonds in several classes organic molecules.

Language: Английский

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Perfluoroalkylation Reactions by Electron Donor‐Acceptor Complexes: Recent Advances

ChemPhotoChem, Journal Year: 2024, Volume and Issue: 8(8)

Published: May 3, 2024

Abstract This Perspective analyses the perfluoroalkylation reactions by electron donor‐acceptor (EDA) complexes since 2018, while summarizes, in Tables , vast majority of representative various classes organic compounds EDA and halogen‐bonding interactions. Numerous intriguing reaction methodologies valuable synthetic instances have emerged. We aim to delve into these new examples comprehensively, also contemplating future directions field. Subsequent sections will elaborate on (hetero)aromatic compounds, carbon‐carbon multiple bonds, carbonyl isocyanides, covering their scope mechanistic insights. Perfluoroalkylation complexes. Entry Substrate Complex Reaction conditions Product Ref. 1 [13] 2 [46] 3 R F I (3 equiv.) KOH (1.5 Blue LEDs H O, Ar, 20 h [47] 4 TEEDA CFL (25 W) THF, r.t. F− [48] 5 ICF CO Et (1.3 Na DMSO mL) rt. 427 nm LED, 16 [49] 6 TMG (2.5 23 W CFL, MeCN/Hex f (5 : 1) [42,50] 7 MeCN [51] 8 Umemoto's reagent (2 N ‐methylmorpholine DMF, [52] 9 Cs white light O r.t., [53] 10 4.5 450 laser CaCl MeNO 0 °C [3] 11 t ‐BuONa DMF Green [54] 12 or complex I−R (2.1 TMEDA DBU 24 [55,56] 13 TFE/water (1 (0.2 M) CF SO [84] bonds constrained cyclic Bu NCl, Hg lamp (6 (1.2 CH OH, 1.5 r.t, Ar [39] [57] DIPEA …….. −I Base THF 25 with DIPEA, TEEDA; [48,58,59] Bn NH [60] Base, [61] O/toluene=9 LEDs, 65 °C, [41] K PO CuCl (10 mol%) TMSNCS CN Violet (24 [37] Diphenylacetaldehyde Pyrrolidine (40 DCE mL); (0.8 eq.); White W); [44,62] DIPEA,DMA (trace air) 36–72 [63] n ‐C air, RT [64] DABCO υ (400 Watt) 50 C 2n+1 (1.8 [65–67] DCE, [27] 14 2,4,6‐trimethylpyridine MeCN, 60 Togni's [68] 15 PMDETA [69] [70,71] 17 less than % water mmol) isocyanides hydrazones. [72,73] cis ‐catalyst M (20 2,6‐lutidine (0.7 ‐10 [74] [75] phase transfer catalyst Cl/8F 18 1), [32] ambient NaOH (4.1 R.T. [76] 36 30 [77] I−C [78] [79] Imidazole [80]

Language: Английский

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Traceless Nucleophile Strategy for C5‐Selective C–H Sulfonylation of Pyridines

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(47)

Published: Aug. 10, 2024

Abstract The functionalization of pyridines is crucial for the rapid construction and derivatization agrochemicals, pharmaceuticals, materials. Conventional approaches have primarily focused on ortho ‐ para ‐positions, while achieving precise meta‐selective functionalization, particularly at C5 position in substituted pyridines, remains a formidable challenge due to intrinsic electronic properties pyridines. Herein, we present new strategy meta C5‐selective C−H sulfonylation N ‐amidopyridinium salts, which employs transient enamine‐type intermediate generated through nucleophilic addition salts. This process harnesses power electron donor‐acceptor complexes, enabling high selectivity broad applicability, including complex bearing valuable sulfonyl functionalities under mild conditions without need an external photocatalyst. remarkable selectivity, combined with applicability late‐stage significantly expands toolbox pyridine unlocking access previously unattainable ‐sulfonylated

Language: Английский

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Nonclassical Arylative Meyer–Schuster Rearrangement through Ni-Catalyzed Inner-Sphere Acyloxy Migration

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(16), P. 10756 - 10764

Published: Aug. 1, 2023

A Ni(II)-catalyzed unconventional Meyer–Schuster rearrangement (MSR) is paired with cross-coupling through inner-sphere acyloxy migration. Various propargyl acetates react aryl boronic acids, leading to the formation of a range α-arylated enone derivatives. This transformation enabled by use P∧N-type phosphinooxazoline (PHOX) ligand, which allows substrate coordinate square planar Ni(II) center. It initiates arylnickelation alkyne moiety followed intramolecular transposition acetate group. nonclassical approach for addition electron-rich nucleophiles at α-position without need redox additives. series controlled experiments including 18O isotope labeling studies and computational analysis corroborated

Language: Английский

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Electrochemical Synthesis of Trifluoromethylated Oxazoles: Aminotrifluoromethylation of Alkynes/in‐situ Cyclization

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(16), P. 3450 - 3454

Published: May 31, 2024

Abstract We report the development of a four‐component electrochemical method for synthesis CF 3 ‐oxazoles, utilizing alkynes and NaSO 2 in MeCN. The leverages simplicity mildness reaction conditions, despite inherent complexity four distinct components through aminotrifluoromethylation alkyne followed by in‐situ cyclization. Notably, addition to MeCN solvent, presence residual water mixture also contributed as coupling partner. involves sequence controlled oxidation steps under constant potential with graphite electrodes, facilitated mediator TMEDA, highlighting precision achievable electrochemistry.

Language: Английский

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Unveiling the Synthetic Potential of Conjugated Organic Molecule as Efficient Photo-catalytic Trifluoromethylation and Photo-cocatalytic C–N Coupling Reaction

Catalysis Letters, Journal Year: 2025, Volume and Issue: 155(2)

Published: Jan. 3, 2025

Language: Английский

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Lighting the Path: A Sustainable Catalyst Free Approach Toward Trifluoromethylation of Indoles

ChemistrySelect, Journal Year: 2025, Volume and Issue: 10(14)

Published: April 1, 2025

Abstract In this study, we report an innovative development of a visible light‐induced synthesis trifluoromethyl indoles. This novel methodology not only obviates the need for traditional catalysts but also harnesses energy photons to selectively introduce groups into indole substrates. Leveraging inexpensive, easily handled, and non‐toxic Langlois reagent (CF 3 SO 2 Na) as CF source, in conjunction with light tert ‐butyl hydrogen peroxide (TBHP), facilitates direct C─H trifluoromethylation The mechanistic pathway reaction is predicted help density functional theory (DFT) calculations at (U)B3LYP/6–31++G(d,p)/SMD/acetonitrile level theory.

Language: Английский

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Progress in Photocatalyzed Trifluoromethylthiolation and Trifluoromethylselenolation Reactions

Synthesis, Journal Year: 2024, Volume and Issue: unknown

Published: May 29, 2024

Abstract The trifluoromethylthio (SCF3) and trifluoromethylselanyl (SeCF3) groups possess high electron-withdrawing ability, excellent lipophilicity, good stability, bioavailability, they are promising structural motifs in drug design development. Photoredox catalysis has clear benefits; it is a mild sustainable methodology for the modification of chemical structures that enables variety reactions unattainable using classical ionic chemistry. This review focuses on light-initiated trifluoromethylthiolation trifluoromethylselenolation with diverse SCF3 SeCF3 reagents. Representative transformations either photocatalysts or through EDA complexes, as well possible reaction mechanisms, all discussed this article. 1 Introduction 2 Photocatalyzed Trifluoromethylthiolation 2.1 MSCF3 (M = H, [Me4N], Ag) 2.2 XSCF3 (X Cl, CF3S) 2.3 ArSO2SCF3 2.4 N–SCF3 Reagents 2.5 Other 3 Trifluoromethylselenolation 3.1 [Me4N][SeCF3] 3.2 ArSO2SeCF3 4 Summary

Language: Английский

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