A dearomatization–rearomatization strategy for construction of 4H-quinolizin-4-ones via C–H bond functionalization of pyridines

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(8), P. 2319 - 2325

Published: Jan. 1, 2024

Herein, the synthesis of 4 H -quinolizin-4-ones from N -(2-methoxy-2-oxoethyl) pyridinium salts and alkenes through dearomative cycloaddition rearomative ring expansion has been developed.

Language: Английский

---

Meta‐Selective Copper‐Catalyzed C–H Arylation of Pyridines and Isoquinolines through Dearomatized Intermediates

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(26)

Published: April 18, 2024

Abstract C(sp 2 )−H functionalization offers an efficient strategy for the synthesis of various elaborated N ‐containing heteroarenes. Along these lines, oxazino pyridines that can be readily prepared from pyridines, have been introduced as powerful substrates in radical‐ and ionic‐mediated meta ‐C−H functionalization. However, regioselective arylation remains a great challenge. Herein, copper‐catalyzed ‐selective C−H isoquinolines through bench‐stable dearomatized intermediates is reported. Electrophilic aryl‐Cu(III) species, generated accessible aryl I(III) reagents, enable ‐arylation broad range isoquinolines. The method also allows alkenylation heteroarenes using corresponding alkenyl I(III)‐reagents. Late‐stage drug‐derived larger‐scale experiments demonstrate potential this synthetic methodology.

Language: Английский

---

Nucleophilic Dearomatization of Activated Pyridines Using Vinyl Sulfoxonium Ylides: Application to the Synthesis of Bis-Heterocycles

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 5, 2024

A highly efficient method has been developed for synthesizing 4-dienyl dihydropyridines through the nucleophilic dearomatization of activated pyridines using vinyl sulfoxonium ylides. This reaction follows sequence involving ylide addition to pyridine, [2,3]-sigmatropic rearrangement, and subsequent sulfenic acid elimination. The resulting are then used in synthesis substituted bis-heterocyles. Control experiments quantum chemical calculations were conducted elucidate selectivity mechanistic pathway.

Language: Английский

---

Electrochemical meta-C−H Sulfonylation of Pyridines with Nucleophilic Sulfinates

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: April 23, 2024

Considering the indispensable significance and utilities of meta-substituted pyridines in medicinal, chemical as well materials science, a direct meta-selective C − H functionalization is paramount importance, but such reactions remain extremely limited highly challenging. In general, established methods for meta rely on utilization tailored electrophilic reagents to realize intrinsic polarity match. Herein, we report complementary electrochemical methodology; diverse nucleophilic sulfinates allow unprecedented meta-sulfonylation through redox-neutral dearomatization-rearomatization strategy by tandem dearomative cycloaddition/hydrogen-evolution electrooxidative sulfonation resulting oxazino-pyridines/acid-promoted rearomatization sequence. Besides, several salient features, including exclusive regiocontrol, remarkable substrate/functional group compatibility, scale-up potential, facile late-stage modification, have been demonstrated, which further contributes practicality adaptability this approach.

Language: Английский

---

Visible-light-induced Ir-catalyzed site-selective C−H trifluoromethylation of 3-substituted 1,2-benzoxazoles

Chemistry of Heterocyclic Compounds, Journal Year: 2024, Volume and Issue: 60(5-6), P. 299 - 303

Published: June 1, 2024

Language: Английский

---