DBU‐Promoted [3 + 2] Cyclization/Retro‐Mannich Cascade Reaction of N‐Aminoisoquinolinium and N‐Aminoquinolinium Derivatives with para‐Quinone Methides

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(9), С. 2003 - 2007

Опубликована: Март 12, 2024

Abstract A DBU‐promoted [3+2] cyclization/retro‐Mannich cascade reaction of N ‐aminoisoquinolinium and ‐aminoquinolinium derivatives with para ‐quinone methides has been established, employing a C=C double bond cleavage. broad range salts, are well tolerated, providing the corresponding rearrangement products. Moreover, scaled‐up reactions diverse derivatizations products were also investigated discussed.

Язык: Английский

---

Tandem (2 + 2) Annulation/Retro-4π Electrocyclization/Imino-Nazarov Cyclization Reaction of p-Quinone Methides with Ynamides: Expeditious Construction of Functionalized Aminoindenes

Organic Letters, Год журнала: 2021, Номер 23(15), С. 5885 - 5890

Опубликована: Июль 19, 2021

A new tandem annulation of p-quinone methides (p-QMs) with ynamides is described. This cascade reaction features a unique combination (2 + 2) annulation, retro-4π electrocyclization, and imino-Nazarov cyclization, wherein vinyl (p-VQMs) as one the key intermediates have been identified chemically. Significantly, an unusual structural reconstruction p-QMs involving cleavage C5–C6 bond late-stage formation C4–C6 involved, leading to methodology development for construction functionalized aminoindenes.

Язык: Английский

---

Formal (3 + 4)-Annulation of Propargylic p-Quinone Methides with 2-Indolylmethanols: Synthesis of Polysubstituted Indole-Fused Oxepines

The Journal of Organic Chemistry, Год журнала: 2021, Номер 86(11), С. 7490 - 7499

Опубликована: Май 18, 2021

A novel Brønsted acid catalyzed 1,8-addition mediated (3 + 4)-annulation of in situ generated propargylic p-quinone methides with 2-indolylmethanols is described. This method provides a convenient and mild approach to structurally interesting synthetically important polysubstituted indole-fused oxepines high yields. Moreover, as four-atom synthons the 4)-annulations under conditions have been explored for first time.

Язык: Английский

---

Palladium-catalyzed asymmetric [4 + 3] cycloaddition of acyclic α,β-unsaturated imines with trimethylenemethane donors: access to chiral non-fused azepines

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(8), С. 2326 - 2331

Опубликована: Янв. 1, 2024

An efficient approach for the construction of non-fused azepines in good yields with high enantioselectivity via Pd-catalyzed asymmetric [4 + 3] cycloaddition was developed.

Язык: Английский

---

Palladium-catalyzed and ligand-controlled divergent cycloadditions of vinylidenecyclopropane-diesters with para-quinone methides enabled by zwitterionic π-propargyl palladium species

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(11), С. 3214 - 3224

Опубликована: Янв. 1, 2024

A palladium-catalyzed and ligand-controlled divergent synthesis of spiro-cyclohexadienones from p -quinone methides VDCP-diesters was realized via zwitterionic π-propargyl palladium species the mechanism clarified by DFT calculations.

Язык: Английский

---

One-Pot Domino Catalysis to Construct Alkyl/Aryl Pyrroles Initiated by Pd-TMM Annulation of Unactivated Imines

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Янв. 9, 2025

Herein, a one-pot domino catalyzed three-component process is described, which initiated by palladium/zinc cooperatively cycloaddition between trimethylenemethane (TMM) and unactivated alkyl/aryl imines, followed isomerization Zn(OTf)2-catalyzed DDQ oxidation, furnishing valuable substituted pyrroles. We disclose that the cooperative catalysis affords dual-Zn(OTf)2-stabilized azapalladacycle, wherein Pd–N bond polarized Zn(OTf)2, facilitating unique outer-sphere allylic amination. Moreover, subsequent dehydrogenation can be feasibly promoted zinc catalysis.

Язык: Английский

---

Photolytic Access to Oxaspirodecanes and Chromenes from Vinyldiazo Ester Cycloaddition with p-Quinones: A Vinylcarbene Is Not Involved

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Март 26, 2025

Synthetic methods that provide access to skeletally diverse heterocyclic motifs are poised accelerate drug discovery and streamline the synthesis of advanced intermediates materials. However, development such synthetic necessitates leveraging previously unexplored mechanistic pathways. We report herein an efficient blue light-emitting diode light-induced reaction vinyldiazoacetates quinones produces spirocyclic dihydrofurans, featuring synthetically challenging oxaspiro[4,5]decane core numerous medicinal agents, agrochemicals, natural products. In a departure from well-established photochemical reactivity diazo compounds, these reactions do not involve vinylcarbene formed by photolytic dinitrogen extrusion. Instead, they result photoexcitation quinone its triplet state with subsequent energy transfer vinyldiazo ester. The addition vinylogous carbon vinyldiazoacetate oxygen affords diradical collapses dihydrofuran upon loss dinitrogen. A strain release-driven Bro̷nsted acid-catalyzed rearrangement products unravels fused bicyclic ring system equally medicinally valuable chromenes, enabling facile skeletal diversification important motifs.

Язык: Английский

---

Iron(iii)-catalyzed tandem annulation of indolyl-substituted p-quinone methides with ynamides for the synthesis of cyclopenta[b]indoles

Chemical Communications, Год журнала: 2022, Номер 58(62), С. 8710 - 8713

Опубликована: Янв. 1, 2022

The unique reactivity of indolyl-substituted p-QMs as a new type two-carbon synthon has been explored for the first time in novel iron(III)-catalyzed tandem annulation. This (2+2) annulation/retro-4π electrocyclization/imino-Nazarov cyclization cascade reaction is characterized by an unusual structural reconstruction p-QMs, leading to expeditious assembly synthetically important functionalized cyclopenta[b]indoles.

Язык: Английский

---

Metal free, one pot 1,6‐Conjugate Addition of Diol on para‐Quinone Methide followed by ipso cyclization: An Approach to Spiro 1,4‐Dioxane cyclohexadienone Derivatives

Chemistry - An Asian Journal, Год журнала: 2022, Номер 17(24)

Опубликована: Окт. 19, 2022

A novel one-pot transition metal-free and Brönsted acid mediated 1,6-conjugate addition of bisnuleophilic diol on biselectrophilc para-quinone methide followed by ipso cyclization assisted NBS has been developed under mild reaction conditions, offers a new approach to synthesize spiro 1,4-dioxane cyclohexadienone derivatives. This strategy features broad substrate scope p-QMs with high functional group tolerance good yields spirocyclic scaffolds (60-92 %). N-Bromo succinimide an important role in spirocyclization efficiency.

Язык: Английский

---

Bismuth(III)-Catalyzed 1,8-Addition/Cyclization/Rearrangement of Propargylic para-Quinone Methides with 2-Vinylphenol: Synthesis of Indeno[2,1-c]chromenes

Organic Letters, Год журнала: 2023, Номер 25(8), С. 1299 - 1304

Опубликована: Фев. 21, 2023

The unique reactivity of in situ generated propargylic para-quinone methides as a new type five-carbon synthon has been discovered by novel bismuth(III)-catalyzed tandem annulation reaction. This 1,8-addition/cyclization/rearrangement cyclization cascade reaction is characterized unusual structural reconstruction 2-vinylphenol, involving cleavage the C1'═C2' bond and formation four bonds. method provides convenient mild approach to generate synthetically important functionalized indeno[2,1-c]chromenes. mechanism proposed from several control experiments.

Язык: Английский

---