Cobalt-Catalyzed Domino Transformations via Enantioselective C–H Activation/Nucleophilic [3 + 2] Annulation toward Chiral Bridged Bicycles

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(22), С. 15576 - 15586

Опубликована: Май 16, 2024

Selective synthesis of chiral bridged (hetero)bicyclic scaffolds via asymmetric C–H activation constitutes substantial challenges due to the multiple reactivities strained bicyclic structures. Herein, we develop domino transformations through an unprecedented cobalt-catalyzed enantioselective activation/nucleophilic [3 + 2] annulation with symmetrical alkenes. The methods offer straightforward access a wide range molecules bearing [2.2.1]-bridged cores four and five consecutive stereocenters in single step. Two elaborate salicyloxazoline (Salox) ligands were synthesized based on rational design mechanistic understanding. well-defined pockets generated from coordination around trivalent cobalt catalyst direct orientation alkenes, leading excellent enantioselectivity.

Язык: Английский

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Parametrization of κ²-N,O-Oxazoline Preligands for Enantioselective Cobaltaelectro-Catalyzed C–H Activations

ACS Catalysis, Год журнала: 2025, Номер unknown, С. 4450 - 4459

Опубликована: Фев. 28, 2025

Enantioselective electrocatalyzed C–H activations have emerged as a transformative platform for the assembly of value-added chiral organic molecules. Despite recent progress, construction multiple C(sp3)-stereogenic centers via C(sp3)–C(sp3) bond formation has thus far proven to be elusive. In contrast, we herein report an annulative activation strategy, generating Fsp3-rich molecules with high levels diastereo- and enantioselectivity. κ2-N,O-oxazoline preligands were effectively employed in enantioselective cobalt(III)-catalyzed reactions. Using DFT-derived descriptors regression statistical modeling, performed parametrization study on modularity preligands. The resulted model describing ligands' selectivity characterized by key steric, electronic, interaction behaviors.

Язык: Английский

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Rh(III)-Catalyzed Alkylation of 8-Methylquinolines with Oxabenzonorbornadienes

Organic Letters, Год журнала: 2023, Номер 25(15), С. 2627 - 2631

Опубликована: Апрель 6, 2023

Herein, a concise Rh(III)-catalyzed C(sp3)-H alkylation of 8-methylquinolines with oxabenzonorbornadiene scaffolds and other strained olefins has been disclosed. The retention the skeleton, broad substrate scope, wide-ranging functional group tolerance are key features developed catalytic methodology. Mechanistic studies revealed that reaction does not involve radical pathway, five-membered rhodacycle is intermediate. This first report on (with ring retention).

Язык: Английский

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Cobalt-Catalyzed Domino Transformations via Enantioselective C–H Activation/Nucleophilic [3+2] Annulation Towards Chiral Bridged Bicycles

Опубликована: Фев. 27, 2024

Selective synthesis of chiral bridged (hetero)bicyclic scaffolds via asymmetric C–H activation constitutes substantial chal-lenges, due to the multiple reactivities strained bicyclic structures. Herein, we develop domino transformations through an unprecedent cobalt-catalyzed enantioselective activation/nucleophilic [3+2] annulation with symmetrical alkenes. The methods offer straightforward accesses a wide range molecules bearing [2.2.1]-bridged bicy-clic cores four and five consecutive stereocenters in single step. Two elaborated salicyloxazoline (Salox) ligands were synthesized based on rational design mechanistic understanding. well-defined pockets generated from coordination around trivalent cobalt catalyst direct orientation alkenes, leading excellent enantioselectivity.

Язык: Английский

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Palladium-Catalyzed [3 + 2] Annulation of Aryl Halides with 7-Oxa- and 7-Azabenzonorbornadienes via C(sp² or sp³)–H Activation

Organic Letters, Год журнала: 2022, Номер 24(49), С. 8964 - 8968

Опубликована: Дек. 1, 2022

A series of epoxybenzo[k]fluoranthenes, epoxy-5H-benzo[b]fluorenes, and their aza analogues have been accessed via palladium-catalyzed exo-selective [3 + 2] annulation between aryl halides 7-oxa- 7-azabenzonorbornadienes. The reaction is initiated by the oxidative addition a carbon-halogen bond, with intramolecular C(sp2 or sp3)-H activation being key step. enantioselective version was also briefly explored.

Язык: Английский

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Ring‐Opening Cyclization of Spirocyclopropanes with Stabilized Phosphorus Ylides: Access to Indane and Azulene Skeletons

Advanced Synthesis & Catalysis, Год журнала: 2023, Номер 365(15), С. 2536 - 2544

Опубликована: Фев. 24, 2023

Abstract In this study, regio‐ and diastereoselective ring‐opening cyclization of spirocyclopropanes with phosphorus ylides stabilized by electron‐withdrawing groups were developed. The reaction various cyclohexane‐1,3‐dione‐2‐spirocyclopropanes bearing alkoxycarbonyl proceeded smoothly without any additives to provide the corresponding 6,7‐dihydroindan‐4‐ones in 32–87% yields. Cycloheptane‐1,3‐dione‐2‐spirocyclopropanes also used reaction, producing products 1,2,3,6,7,8‐hexahydroazulen‐4‐ones 52–67% resulting [5.6]‐ [5.7]‐fused carbocyclic readily converted into highly substituted indanes azulenes, respectively, oxidation.

Язык: Английский

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Recent Advances in Transition‐Metal‐Catalyzed Ring‐Retentive Addition Reactions of Oxa(aza)benzonorbornadienes

Advanced Synthesis & Catalysis, Год журнала: 2023, Номер 365(24), С. 4440 - 4457

Опубликована: Ноя. 22, 2023

Abstract Oxa(aza)benzonorbornadienes are utilized as important synthetic intermediates and useful building blocks in organic synthesis due to their structural features reactivity. In addition ring‐opening reactions, the transition‐metal‐catalyzed ring‐retentive reactions of oxa(aza)bicyclic alkenes have increasingly drawn attention various researchers. Numerous efficient protocols this field been investigated that enable facile transformations oxa(aza)benzonorbornadienes related valuable adducts, which summarized discussed detail review.

Язык: Английский

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Synthesis of Cobalt Complexes and Study of Their Catalytic Activities in Various Organic Transformations

Springer proceedings in physics, Год журнала: 2024, Номер unknown, С. 87 - 108

Опубликована: Дек. 28, 2024

Язык: Английский

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