Three-component synthesis ofN-naphthyl pyrazolesviaRh(iii)-catalyzed cascade pyrazole annulation and Satoh–Miura benzannulation

Chemical Communications, Год журнала: 2023, Номер 59(27), С. 4036 - 4039

Опубликована: Янв. 1, 2023

The synthesis of N-naphthyl pyrazoles has been realized by the direct three-component reactions enaminones, aryl hydrazine hydrochlorides and internal alkynes via Rh(III) catalysis. synthetic employing simple substrates lead to simultaneous construction dual cyclic moieties, including a pyrazole ring phenyl ring, sequential formation two C-N three C-C bonds.

Язык: Английский

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Three-Component Chemo-Selective Synthesis of N-(o-Alkenylaryl) Pyrazoles by Pyrazole Annulation and Rh-Catalyzed Chemo-Selective Aryl C–H Addition Cascade

The Journal of Organic Chemistry, Год журнала: 2023, Номер 88(13), С. 8619 - 8627

Опубликована: Май 31, 2023

By using readily available enaminones, aryl hydrazine hydrochlorides, and alkynes as starting materials, the chemo-selective three-component synthesis of atropisomeric N-(o-alkenylaryl) pyrazoles has been efficiently accessed with rhodium catalysis. Unlike Satoh-Miura reaction leading to alkyne-based C-H benzannulation by prior prepared N-phenyl substrates, this protocol displays unprecedented selectivity alkenylation blocking second round metal key protonation step in presence acids.

Язык: Английский

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Rhodium‐Catalyzed Dual C−H Activation for Regioselective Triple Annulation of Enaminones: Access to Polycyclic Naphthopyran Derivatives

Advanced Synthesis & Catalysis, Год журнала: 2023, Номер 365(11), С. 1770 - 1776

Опубликована: Март 21, 2023

Abstract Rh‐catalyzed C−H activation of arenes for oxidative annulations with alkynes stands out as a protocol polycyclic scaffolds. This perspective drives us to disclose herein rhodium catalyzed regioselective triple annulation enaminones hydroxyl‐alkynoates via double functionalization naphtho‐pyran Secondary coordination OH in alkynoate dictated the regioselectivity. Initial lactonization occurred chemoselectively on enamine part carbo rhodation followed by reductive elimination. was scalable and has shown high functionality tolerance. KIE studies were done get insight mechanism, some downstream transformations achieved show synthetic potential method.

Язык: Английский

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Recent Progress in Application of Propargylic Alcohols in Organic Syntheses

Advanced Synthesis & Catalysis, Год журнала: 2023, Номер 365(18), С. 2991 - 3019

Опубликована: Июль 14, 2023

Abstract Propargylic alcohols are readily available bifunctional (alkyne and hydroxyl groups) synthons, which recognize as one of the attractive synthetic feedstock in organic transformations. Especially, recent years employment these valuable molecules has frequently been observed literature. Hence, present review highlights advancements application propargylic cyclization, substitution, addition reactions.

Язык: Английский

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Rhodium-Catalyzed Regioselective Double Annulation of Enaminones with Propargyl Alcohols: Rapid Access to Arylnapthalene Lignan Derivatives

The Journal of Organic Chemistry, Год журнала: 2021, Номер 87(2), С. 1240 - 1248

Опубликована: Дек. 29, 2021

We present here a rhodium-catalyzed oxidative three-point double annulation of enaminones with propargylic alcohols via C–H and C–N bond activation to access arylnaphthalene-based lignan derivatives. The key step in the reaction is regioselective insertion alcohol into rhoda-cycle, result hydroxyl rhodium coordination. Necessary control experiments KIE studies were conducted determine mechanism.

Язык: Английский

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Sonogashira Cross-Coupling of Aryl Ammonium Salts by Selective C–N Activation Catalyzed by Air- and Moisture-Stable, Highly Active [Pd(NHC)(3-CF₃-An)Cl₂] (An = Aniline) Precatalysts

Organic Letters, Год журнала: 2022, Номер 24(34), С. 6310 - 6315

Опубликована: Авг. 24, 2022

We report the Sonogashira cross-coupling of aryl ammonium salts catalyzed by air- and moisture-stable [Pd(NHC)(3-CF3-An)Cl2] (An = aniline). This highly active Pd(II)–NHC complex features broad scope excellent C–N activation selectivity in challenging alkynylative salts. Full structural characterization computational studies demonstrate effect pyridine to aniline replacement as effective stabilizing ancillary ligand well-defined Pd(II)–NHCs. Considering high reactivity recent commercialization (Millipore Sigma, no. 915165), this catalyst represents an attractive approach bonds synthetic interest.

Язык: Английский

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Palladium-Catalyzed Carbo-Aminative Cyclization of 1,6-Enynes: Access to Napthyridinone Derivatives

Organic Letters, Год журнала: 2022, Номер 24(8), С. 1598 - 1603

Опубликована: Фев. 22, 2022

1,6-Enynes have recently stimulated enormous attention toward paving the way to unique cascade cyclizations offering complex cyclic motifs from linear substrates. We describe herein a general approach napthyridinones via Pd-catalyzed annulation of 1,6-enynes with 2-iodoanilines. This protocol represents rare carbo-aminative annulative cyclization 6-endo-trig mode, subduing well-documented exo-trig/dig cyclizations. The regioselective aryl palladation alkyne followed by Heck-type intramolecular coupling before isomerization were key in realizing this cascade.

Язык: Английский

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Rhodium-Catalyzed Coordination-Assisted Regioselective and Migratory Three-Point Double Annulation of o-Alkenyl Phenols with Tertiary Propargyl Alcohols

Organic Letters, Год журнала: 2022, Номер 24(28), С. 5062 - 5067

Опубликована: Июль 11, 2022

We disclose herein a Rh(III)-catalyzed migratory three-point double annulation of o-alkenyl phenols with propargyl alcohols for de novo construction naphtho furan derivatives in regio- and chemoselective manner. The protocol orchestrates two new rings four bonds one operation without the need any additive. Necessary labeled control experiments are conducted to elucidate reaction mechanism. A tertiary hydroxyl group is found be crucial both controlling regioselective insertion alkyne through chelation rhodium form key spiro cyclic intermediate forcing ring expansion via unusual selective olefin reshuffling, apart from forming an extra (furan) ring. scalable shows tolerance late stage functionalization natural products.

Язык: Английский

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Propargyl Alcohols as Bifunctional Reagents for Divergent Annulations of Biphenylamines via Dual C−H Functionalization/Dual Oxidative Cyclization

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(12)

Опубликована: Дек. 30, 2022

The C-H functionalization strategy provides access to valuable molecules that previously required convoluted synthetic attempts. Dual unsymmetrical functionalization, with a single bifunctional reagent, is an effective tactic. Propargyl alcohols (PAs), despite containing reactive C≡C bond, have not been explored as building blocks via oxidative cleavage. Annulations activation are versatile and synthetically attractive strategy. We disclose PA new reagent for dual of biphenylamine regioselectively annulated outcomes. On tuning the conditions, annulation bifurcated towards unusual cyclization. This method accommodates wide range PAs showcases late-stage diversification some natural products.

Язык: Английский

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Pd-Catalyzed Chelation-Assisted Regioselective and Site Selective Cyclative C–H Annulation of Alkynyl Oximes with Activated Alkynes

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(6), С. 3834 - 3843

Опубликована: Фев. 29, 2024

Electrophilic cyclization and concomitant C–H annulation constitute an expedient cascade strategy for the construction of multicyclic scaffolds with precise substitutional patterns. We report here a novel Pd-catalyzed cyclative ynone oxime activated alkynes. The features dual regioselectivity including site selective activation chelation-assisted insertion Control experiments together kinetic give insights into mechanism.

Язык: Английский

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