Lewis Acid‐Catalyzed Unusual (4+3) Annulation of para‐Quinone Methides with Bicyclobutanes: Access to Oxabicyclo[4.1.1] octanes

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(48)

Опубликована: Авг. 22, 2024

Over the past few years, there has been a surge of interest in chemistry bicyclobutanes (BCBs). Although BCBs have used to synthesize bicyclo[2.1.1]hexanes and bicyclo[3.1.1]heptanes, synthesis bicyclo[4.1.1]octanes remained elusive. Herein, we report first Lewis acid-catalyzed unexpected (4+3) annulation para-quinonemethides (p-QMs) with allowing oxabicyclo[4.1.1]octanes proceeding under mild conditions. With 5 mol % Bi(OTf)

Язык: Английский

---

Intermolecular Formal [2π + 2σ] Cycloaddition of Enol Silyl Ethers with Bicyclo[1.1.0]butanes Promoted by Lewis Acids

Organic Letters, Год журнала: 2024, Номер 26(30), С. 6309 - 6313

Опубликована: Июль 23, 2024

Silyl enol ethers react with bicyclo[1.1.0]butanes (BCBs) through Yb(OTf)

Язык: Английский

---

Divergent Enantioselective Access to Diverse Chiral Compounds from Bicyclo[1.1.0]butanes and α,β-Unsaturated Ketones under Catalyst Control

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Сен. 30, 2024

Achieving structural and stereogenic diversity from the same starting materials remains a fundamental challenge in organic synthesis, requiring precise control over selectivity. Here, we report divergent catalytic methods that selectively yield either cycloaddition or addition/elimination products bicyclo[1.1.0]butanes α,β-unsaturated ketones. By employing chiral Lewis acid Brønsted catalysts, achieved excellent regio-, diastereo-, enantioselectivity across all three distinct transformations, affording diverse array of synthetically valuable bicyclo[2.1.1]hexanes cyclobutenes. The outcomes are controlled by differential activation substrates specific catalyst with reaction conditions dictating pathway This strategy demonstrates power catalysis creating molecular complexity diversity, offering tool for synthesis enantioenriched building blocks.

Язык: Английский

---

Ring Expansion toward Fused Diazabicyclo[3.1.1]heptanes through Lewis Acid Catalyzed Highly Selective C−C/C−N Bond Cross‐Exchange Reaction between Bicyclobutanes and Diaziridines

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 13, 2024

Abstract The synthesis of bicyclic scaffolds has garnered considerable interest in drug discovery because their ability to mimic benzene bioisosteres. Herein, we introduce a new approach that utilizes Lewis acid (Sc(OTf) 3 )‐catalyzed σ‐bond cross‐exchange reaction between the C−C bond bicyclobutanes and C−N diaziridines produce multifunctionalized medicinally interesting azabicyclo[3.1.1]heptane derivatives. proceeds well with different broad range aryl‐ as alkenyl‐, but also alkyl‐substituted (up 98 % yield). Conducting scale‐up experiment exploring synthetic transformations cycloadducts emphasized practical application synthesis. Furthermore, zinc‐based chiral catalytic system was developed for enantioselective version this 96 ee ).

Язык: Английский

---

In(OTf)₃-Catalyzed (3 + 3) Dipolar Cyclization of Bicyclo[1.1.0]butanes with N-Nucleophilic 1,3-Dipoles: Access to 2,3-Diazabicyclo[3.1.1]heptanes, 2,3-Diazabicyclo[3.1.1]heptenes, and Enantiopure 2-Azabicyclo[3.1.1]heptanes

ACS Catalysis, Год журнала: 2024, Номер unknown, С. 17837 - 17849

Опубликована: Ноя. 18, 2024

The investigation into the synthesis of azabicyclo[3.1.1]heptanes (azaBCHeps) as bioisosteres to flat aza-aromatics has garnered increasing attention, while it encounters significant challenges. Herein, we have demonstrated In(OTf)3-catalyzed (3 + 3) dipolar cyclization bicyclo[1.1.0]butanes (BCBs) with hydrazones and π-allyl-iridium 1,3-dipoles, engendering a diverse array azaBCHeps. BCBs furnished densely substituted 2,3-diazabicyclo[3.1.1]heptanes 2,3-diazabicyclo[3.1.1]heptenes under nitrogen oxygen atmospheres, respectively. A combination experimental computational investigations lends robust support for proton-transfer-interposed sequential mechanism. More importantly, by integrating In(OTf)3/iridium relay catalysis, enantiopure 2-azabicyclo[3.1.1]heptanes were constructed through aza-π-allyl-iridium in situ generated from N-allyl carbonates. Both methodologies exhibit mild reaction conditions good tolerance various functional groups. Moreover, copious derivatization products highlights utility newly synthesized heterobicyclic motifs versatile building blocks synthetic chemistry.

Язык: Английский

---

Lewis Acid-Catalyzed Asymmetric [2σ + 2π] Cycloaddition Reactions of Bicyclo[1.1.0]butanes and Vinyl Azido/Diazo Compounds

ACS Catalysis, Год журнала: 2025, Номер unknown, С. 4634 - 4643

Опубликована: Март 4, 2025

Язык: Английский

---

Enantioselective [2π + 2σ] cycloaddition of bicyclobutanes with imines: An efficient approach to chiral 2-aza-bicyclo[2.1.1]hexanes

Chem Catalysis, Год журнала: 2025, Номер unknown, С. 101295 - 101295

Опубликована: Март 1, 2025

Язык: Английский

---

Enantioselective Dearomative [2π + 2σ] Photocycloaddition of Naphthalene Derivatives with Bicyclo[1.1.0]butanes Enabled by Gd(III) Catalysis

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

Опубликована: Март 28, 2025

The cycloaddition reactions of bicyclo[1.1.0]butanes with alkenes, imines, nitrones, or aziridines have served as an efficient platform to create conformationally restricted saturated bicyclic scaffolds. However, the use readily available aromatics in such reactions, especially asymmetric manner, remains underexplored. Herein, we report a highly regio- and enantioselective dearomative [2π + 2σ] photocycloaddition reaction between naphthalene derivatives bicyclo[1.1.0]butanes, enabled by Gd(III) catalysis. Bicyclo[1.1.0]butanes naphthalenes adorned diverse array functional groups are well-tolerated under mild conditions, affording enantioenriched pharmaceutically important bicyclo[2.1.1]hexanes 30–96% yields 81–93% ee 12:1 → >20:1 rr. synthetic versatility this is further demonstrated facile removal directing group derivatizations dearomatized product. UV–vis absorption spectroscopy studies suggest involvement excited species process.

Язык: Английский

---

Conditions-Controlled Divergent Annulation of Bicyclo[1.1.0]butanes and Dioxopyrrolidines through Lewis Acid Catalysis

ACS Catalysis, Год журнала: 2025, Номер unknown, С. 6025 - 6035

Опубликована: Март 28, 2025

Язык: Английский

---

Ag(I)-Catalyzed Tandem Cyclization–Cycloaddition–Isomerization Reaction of 2-Alkynylbenzaldoxime with Bicyclobutane: A Route to Multiply Substituted Cyclobutanols

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Апрель 1, 2025

Multiply substituted cyclobutanols are pivotal synthetic intermediates for constructing complex molecular architectures via ring-opening strategies. The development of efficient methods these valuable building blocks has garnered significant interest in the chemical community. In this work, we have described a novel silver(I)-catalyzed tandem cyclization–cycloaddition–isomerization sequence with bicyclobutanes and 2-alkynylbenzaldoximes, which offered an effective route to multiply cyclobutanols. This protocol features mild conditions, remarkable stereospecificity, broad substrate scope, excellent functional group tolerance. addition, application potential reaction was readily proven by its high efficiency reactants bearing biological moieties scale-up experiments.

Язык: Английский

---