Stereodivergent Synthesis of Spiroaminals via Chiral Bifunctional Hydrogen Bonding Organocatalysis

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(22)

Опубликована: Апрель 2, 2024

Spiroaminals represent novel structural motifs prevalent in diverse natural products and biologically active molecules. Achieving their enantioselective synthesis is a highly desirable challenging task synthetic endeavors due to intricate molecular frameworks. Herein, we accomplished the first stereodivergent construction of spiroaminals using chiral bifunctional organocatalyzed intramolecular 1,2-addition followed by an oxa-Michael addition cascade high atom step economical pathway. A proper modulation cinchona-derived squaramide catalysts efficiently provided access all possible stereoisomers with yield, diastereoselectivity, excellent enantioselectivity while displaying broad substrate tolerance. Additionally, validated scalability reaction demonstrated variable spiroaminal scaffolds, confirming viability our protocol.

Язык: Английский

---

Enantioselective synthesis of spiro-N,O-ketals via iridium and Brønsted acid co-catalyzed asymmetric formal [4+2] cycloaddition

Chemical Communications, Год журнала: 2024, Номер 60(11), С. 1448 - 1451

Опубликована: Янв. 1, 2024

An asymmetric formal [4+2] cycloaddition of cyclic enamides with 2-(1-hydroxyallyl)phenol via iridium and Brønsted acid co-catalysis has been achieved to afford chiral N -unsubstituted spiro- , O -ketals.

Язык: Английский

---

Visible Light‐Enhanced C−H Amination of Cyclic Ethers with Iminoiodinanes

Advanced Synthesis & Catalysis, Год журнала: 2022, Номер 364(23), С. 4061 - 4068

Опубликована: Ноя. 5, 2022

Abstract A two‐step protocol allowing the C−H amination of cyclic ethers with iminoiodinanes, followed by reduction resulting intermediate has been developed for preparation amino alcohols. The initial functionalization is accelerated visible light, improving reactivity compared to thermal process performed in dark. effect different substituents on photochemical iminoiodinanes studied both experimentally and computationally. Photophysical measurements DFT calculations were better understand observed reactivities corroborate proposed mechanistic proposal. magnified image

Язык: Английский

---

Tandem Synthesis of Pyrrolidine and Piperidine Derivatives from Propargylic Alcohols Under Multimetallic Catalysis

European Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Апрель 28, 2025

Herein reported is tandem synthesis of 2‐carbonylmethyl pyrrolidine/piperidine derivatives from propargylic alcohols under multimetallic catalysis. A Meyer–Schuster rearrangement cationic Au catalysis, followed by in situ olefin cross‐metathesis with appropriately protected amino olefins delivered α,β‐unsaturated ketones, which without isolation underwent an intramolecular aza‐Michael addition to afford a variety pyrrolidine and piperidine derivatives. The scope the present reaction investigated show that common amine protecting groups, such as Ts, Ns, Cbz, Bz, are well tolerated. Addition catalytic amount bismuth(III) triflate required for promoting where N‐protected group less nucleophilic. stereochemical consequence found be dependent on group.

Язык: Английский

---

Alkoxy Radical‐Triggered 1,1,2‐Trifunctionalization of Unactivated Alkenes towards N,O‐Spiroaminals

Chinese Journal of Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Апрель 18, 2025

Comprehensive Summary N,O‐Spiroaminals have potential biological activities and abilities to modulate the physicochemical pharmacokinetic properties of drug molecules. However, effective catalytic methods for efficient construction N,O‐spiroaminals are still limited date. Herein, we report a novel 1,1,2‐trifunctionalization unactivated alkenes rapidly efficiently obtain diverse array architecturally intriguing N,O‐spiroaminals. This methodology exhibits broad substrate scope, good functional group compatibility, synthetic utility by scale‐up reaction, product derivatizations late‐stage functionalization complex biorelevant molecule. Notably, this transformation selectively allows formation three new chemical bonds (C–O, C–C, C–N) one spiro quaternary carbon center across C‐C double bonds.

Язык: Английский

---

One-Pot Double Intramolecular Cyclization Approach to Tetralin-Based Cis-Fused Tetracyclic Compounds

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(8), С. 5085 - 5096

Опубликована: Март 25, 2022

Presented herein is a BF3·OEt2-mediated, diastereoselective one-pot double cyclization of 4-aryl-2-[(arylthio)methyl]butanals leading to the formation cis-tetrahydro-6H-naphtho[2,1-c]thiochromenes for first time. Mechanistically, title products involves intramolecular Friedel-Crafts hydroxyalkylation/intramolecular alkylation cascade. This synthetic methodology featured by its high atom economy, broad substrate scope, mild transition-metal-free reaction conditions, capability assemble two new rings in one pot, and moderate yields (up 94% yield). It was then applied synthesis thia analogue brazilane chromeno[3,4-c]chromene derivative. Moreover, successfully extended cis-hexahydrobenzo[c]phenanthrenes. Specifically, 1,5-diarylpentan-3-ones were subjected Corey-Chaykovsky reaction, resulting epoxides, without being chromatographically isolated, treated with BF3·OEt2 afford cyclized 84% yield over steps).

Язык: Английский

---

Tandem Synthesis of 1,2,3-Thiadiazoles with 3,4-Dichloroisothiazoles and Hydrazines under External Oxidant- and Sulfur-Free Conditions

Organic Letters, Год журнала: 2022, Номер 24(36), С. 6599 - 6603

Опубликована: Сен. 2, 2022

1,2,3-Thiadiazoles are among the most important heterocyclic motifs, with wide applications in natural products and medicinal chemistry. Herein, we disclose a tandem reaction for synthesis of structurally diverse 1,2,3-thiadiazoles from 3,4-dichloroisothiazol-5-ketones hydrazines. This method is characterized by mild external oxidant- sulter-free conditions, broad substrate scope, easy purification.

Язык: Английский

---

Indium-catalyzed synthesis of benzannulated spiroketals by intramolecular double hydroalkoxylation of ortho-(hydroxyalkynyl)benzyl alcohols

Organic Chemistry Frontiers, Год журнала: 2022, Номер 9(24), С. 6894 - 6901

Опубликована: Янв. 1, 2022

The novel indium-catalyzed synthesis of benzannulated spiroketals by a double intramolecular hydroalkoxylation reaction o -(hydroxyalkynyl)benzyl alcohols is reported.

Язык: Английский

---

Stereodivergent Synthesis of Spiroaminals via Chiral Bifunctional Hydrogen Bonding Organocatalysis

Angewandte Chemie, Год журнала: 2024, Номер unknown

Опубликована: Апрель 2, 2024

Abstract Spiroaminals represent novel structural motifs prevalent in diverse natural products and biologically active molecules. Achieving their enantioselective synthesis is a highly desirable challenging task synthetic endeavors due to intricate molecular frameworks. Herein, we accomplished the first stereodivergent construction of spiroaminals using chiral bifunctional organocatalyzed intramolecular 1,2‐addition followed by an oxa‐Michael addition cascade high atom step economical pathway. A proper modulation cinchona‐derived squaramide catalysts efficiently provided access all possible stereoisomers with yield, diastereoselectivity, excellent enantioselectivity while displaying broad substrate tolerance. Additionally, validated scalability reaction demonstrated variable spiroaminal scaffolds, confirming viability our protocol.

Язык: Английский

---

4‐Aryl‐1H‐isochromenes Synthesis from Triol Derivatives through Brønsted Acid‐Catalyzed Pinacol Rearrangement/Intramolecular Cyclization Sequence

Asian Journal of Organic Chemistry, Год журнала: 2023, Номер 13(2)

Опубликована: Дек. 6, 2023

Abstract 4‐Aryl‐1 H ‐isochromene derivatives have been successfully synthesized by Brønsted acid‐catalyzed pinacol rearrangement/intramolecular cyclization of the substituted 1‐(2‐(hydroxymethyl)phenyl)‐2‐arylethane‐1,2‐diols. The reaction generally proceeded with low catalyst loading trifluoromethanesulfonic acid (5 mol%) for short times (10‐20 min) to furnish desired 4‐aryl‐1 ‐isochromenes which were subsequently hydrogenated 4‐aryl‐isochromans up 90 % yield. Moreover, oxidation resulting 4‐aryl‐isochroman provided 4‐aryl‐isochroman‐1‐one in good

Язык: Английский

---