Access to Enantiopure Spiropyridines Enabled by Enantio-Relay Double [2 + 2 + 2] Cycloaddition and Kinetic Resolution [2 + 2 + 2] Cycloaddition of Alkynes and Nitriles

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 11, 2025

The synthesis of enantiopure and structurally unique spiro-type molecules is utmost significance in catalysis, synthetic chemistry, related fields. We present here a general solution, nickel-catalyzed [2 + 2 2] cycloaddition, for accessing enantioenriched spiropyridines from readily available nitriles alkynes single step, including (1) enantio-relay double cycloaddition malononitriles with (2) kinetic resolution racemic pyridine-containing alkynes. Both strategies feature broad substrate scope exclusive regioselectivities, are scalable to multigram. Remarkably, the integrates enantio-induction by desymmetrizing dinitriles during initial catalytic cycle additional enantio-enhancement second (enantio-relay), yielding excellent enantioselectivities (>99% ee all examined examples). Furthermore, highly efficient strategy enables achievement exceptionally high without compromising yields (s > 200 most examples), overcoming challenges toward yield enantioselectivity. ability construct previously inaccessible spiro structures lays groundwork advancing spiropyridine derivatives, especially multinitrogen-containing compounds as potential ligands. Due perpendicular molecular orientation inherent rigidity architectures obtained, we anticipate significant promise presented approaches enhancing efforts catalysis.

Language: Английский

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Norrish-Yang-type cyclopropanation via functional group migration with photosensitizer at ppb loading

Chem Catalysis, Journal Year: 2024, Volume and Issue: unknown, P. 101099 - 101099

Published: Sept. 1, 2024

Language: Английский

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Assembly of Fluoranthenes via Cobalt-Catalyzed [2 + 2 + 2] Cycloaddition of 1,6-Diynes with Alkynes

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

Published: Feb. 13, 2025

A series of polyaryl-substituted fluoranthenes is built in good to excellent yields via Earth-abundant metal-catalyzed [2 + 2+ 2] cycloaddition 1,6-diynes with alkynes developed. This method runs smoothly using a cheap catalytic system (CoI2/dppe/Zn) as the catalyst. Generally, this strategy exhibits low cost, high efficiency, atom economy, and functional group tolerance. Additionally, both terminal alkynes, especially heteroaryl-substituted acetylenes, internal alkyne, tolerate work. Furthermore, photophysical properties selected also investigated.

Language: Английский

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Access to Polysubstituted Pyrimidin-2-ones by Pd-Catalyzed [2 + 2 + 2] Cycloaddition of Alkyne-Tethered Malononitriles and Isocyanates

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: May 5, 2025

Transition-metal-catalyzed [2 + 2 2] cycloaddition reactions of alkynes, nitriles, and other π partners have been recognized as economic strategies to assemble aza-six-membered rings, but access pyrimidin-2-ones is not disclosed. Herein, we report a palladium-catalyzed 1,3-diyne-substituted malononitriles isocyanates for the construction polysubstituted pyrimidin-2-ones. This reaction features broad substrate scope moderate high yields. Conjugated pyrimidin-2-one acting fluorophore showcased potential fluorescent chemosensor Fe(III) detection.

Language: Английский

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Concise synthesis of succinimide-fused 1,3-cyclohexadienes via Co-catalyzed [2 + 2 + 2] cycloaddition of 1,6-diynes and maleimides

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(11), P. 3257 - 3262

Published: Jan. 1, 2024

This work has realized a facile assembly of succinimide-fused 1,3-cyclohexadienes via Co-catalyzed [2 + 2 2] cycloaddition 1,6-diynes to maleimides. Furthermore, the oxidation was carried out under I /MeONa.

Language: Английский

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Pd/Cu Dual Metal-Catalyzed Regioselective [2 + 2 + 2] Cycloaddition of Malononitriles with Alkynes to Densely Substituted Pyridines

Organic Letters, Journal Year: 2024, Volume and Issue: 26(35), P. 7324 - 7329

Published: Aug. 22, 2024

Transition metal-catalyzed [2 + 2 2] cycloaddition of nitriles and two alkynes is an efficient method for assembling pyridines. However, examples employing palladium catalysis have rarely been disclosed, the processes reactivity selectivity remain unclear. We report here a palladium/copper dual diynyl-tethered malononitriles terminal to synthesize densely substituted This features good substrate scope, synthetically useful yields, perfect regioselectivity. The derivatization pyridine products demonstrates potential application this in synthesizing heterocycles as ligands photocatalysis. Preliminary mechanistic studies suggest that reaction undergoes aza-oxidative Pd(0) with nitrile alkyne, followed by alkyne insertion reductive elimination. presence copper crucial its

Language: Английский

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Synthesis of Polyaryl‐Substituted Azafluoranthenes via Co‐Catalyzed [2+2+2] Cycloaddition of 1,6‐Diynes with Nitriles

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 8, 2024

Abstract Herein, we demonstrate the synthesis of azafluoranthene derivatives under mild conditions via [2+2+2] cycloaddition 1,6‐diynes and nitriles catalyzed by CoBr 2 /dppp, exhibiting good atom economy. This procedure uses an inexpensive ligand earth‐abundant metal as catalyst to lower cost synthesis. Several azafluoranthenes are produced in 28–95% yields using this approach, featuring conditions, wide substrate scope, functional group tolerance. The fluorescence spectra some indicate that these scaffolds have photophysical properties for material science.

Language: Английский

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