Cis-Selective Double Spirocyclization via Dearomatization and Isomerization under Thermodynamic Control

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(3), P. 1803 - 1814

Published: Jan. 12, 2023

Spiro compounds have been considered key scaffolds for pharmaceutical applications. Although many synthetic methods exist monospirocycles, fewer approaches are known dispirocycles. Here, we report a highly cis-selective method constructing 5/6/5-dispirocyclic structure containing pyrrolidine and γ-lactam rings with various substituents from series of N-arylpropiolamides. The high cis-selectivity would result isomerization under thermodynamic control. Cis- trans-diastereomers can be in equilibrium, favoring cis-adducts.

Language: Английский

---

Synthesis of New 4′-(Substituted phenyl)spiro[indoline-3,3′-[1,2,4]triazolidine]-2,5′-diones as Antimicrobial, Antitubercular, and Antifungal Agents: An Insight into the ADME and Toxicity Prediction as well as in-silico Molecular Docking Studies

Journal of Molecular Structure, Journal Year: 2023, Volume and Issue: 1290, P. 135846 - 135846

Published: May 23, 2023

Language: Английский

---

Recent Developments on the Synthesis of Oxygen- and Sulfur-containing Heterocycles and their Derivatives under Visible Light Induced Reactions

Current Topics in Medicinal Chemistry, Journal Year: 2024, Volume and Issue: 25(1), P. 124 - 140

Published: July 4, 2024

Visible-light-mediated reactions have recently emerged as a powerful strategy for the synthesis of diverse organic molecules under mild reaction conditions. Usually, are performed at room temperature and thus sensitive functional groups remain unaffected. Thus, this protocol has received intense interest from academia well industries. The heterocycles, in general, much because their biological activities application therapeutics. Oxygen- Sulfur-containing heterocyclic compounds attracted attention these showed promising anti-cancer drugs, antibiotics, antifungal anti-inflammatory agents among other applications. class by efficient greener routes become an important target. This review highlights various procedures derivatives visible light-induced reactions. green aspects mechanism each procedure been discussed.

Language: Английский

---

Metal‐Free Intramolecular Hydroalkoxylation of Alkyne: Recent Advances

ChemistrySelect, Journal Year: 2021, Volume and Issue: 6(33), P. 8511 - 8526

Published: Sept. 1, 2021

Abstract Hydroalkoxylation of alkyne offers a unique platform to rapidly access structurally complex and densely functionalized oxygen‐bearing heterocycles. Further, enhance the synthetic utility, various cascade reactions including hydroalkoxylation have been reported in both stereo‐ as well enantioselective manner under metal metal‐free conditions. A collection most representative recent methods employing events are presented this review article.

Language: Английский

---

Multiphotocatalyst Cascades: From Furans to Fused Butyrolactones and Substituted Cyclopentanones

Organic Letters, Journal Year: 2022, Volume and Issue: 24(48), P. 8786 - 8790

Published: Nov. 23, 2022

High value oxygenated polycycles have been rapidly and efficiently accessed from simple precursors in one pot processes. The reported methodology relies on a new mild method for butenolide synthesis mediated by thiols. initial photooxygenation merged with subsequent photoredox reactions to achieve rare dual-photocatalyst cascades affording various fused butyrolactones. Ground state Lewis acid activity methylene blue has unveiled then exploited the of substituted cyclopentanones.

Language: Английский

---

Entry to new spiroheterocycles via tandem Rh(II)-catalyzed O–H insertion/base-promoted cyclization involving diazoarylidene succinimides

Beilstein Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 20, P. 561 - 569

Published: March 11, 2024

A facile approach to novel medicinally relevant spiro heterocyclic scaffolds (namely furan-2(5 H )-ones, tetrahydrofurans and pyrans spiro-conjugated with the succinimide ring) has been developed. The protocol consists of Rh(II)-catalyzed insertion carbenes derived from diazoarylidene succinimides (DAS) into O–H bond propiolic/allenic acids or brominated alcohols, followed by base-promoted cyclization afford target spirocyclic compounds in good high yields.

Language: Английский

---

Non‐Bonding 1,4‐Sulphur‐Oxygen Interaction Governs the Reactivity of α‐Ketothioesters in Triphenylphosphine‐Catalyzed Cyclization with Acetylenedicarboxylates

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 363(4), P. 1014 - 1021

Published: Dec. 22, 2020

Abstract α‐Ketothioesters undergo triphenylphosphine (PPh 3 )‐catalyzed cyclization with acetylenedicarboxylate esters smoothly, in contrast to α‐ketooxoesters which require more drastic conditions the limited substrate scope. The reaction works well a wide range of α‐ketothioesters, delivering highly functionalized α,β‐unsaturated γ‐butyrolactones moderate excellent yields. higher reactivity thioester derivatives is seemingly due favourable intramolecular non‐bonding electrostatic 1,4‐interaction involving C−S σ* orbital on sulphur atom and lone pair electrons electron‐donating oxygen atom. This apparent from X‐ray crystallographically determined internuclear distance between ketone (C=O) atoms (2.71–2.85 Å), significantly less than sum their van der Waals radii (3.25–3.30 Å). substitution S oriented diametrically away O maximize interaction them. trend also seen 1,4‐S⋅⋅⋅O contact furan (2.70 Å) γ‐butyrolactone products. magnified image

Language: Английский

---

Tailored Synthesis of Skeletally Diverse Stemona Alkaloids through Chemoselective Dyotropic Rearrangements of β‐Lactones

Angewandte Chemie, Journal Year: 2021, Volume and Issue: 133(26), P. 14666 - 14674

Published: April 14, 2021

Abstract The collective synthesis of skeletally diverse Stemona alkaloids featuring tailored dyotropic rearrangements β‐lactones as key elements is described. Specifically, three typical 5/7/5 tricyclic skeletons associated with stemoamide, tuberostemospiroline and parvistemonine were first accessed through chemoselective involving alkyl, hydrogen, aryl migration, respectively. By the rational manipulation substrate structures reaction conditions, these proceeded excellent efficiency, good chemoselectivity high stereospecificity. Furthermore, several polycyclic alkaloids, including saxorumamide, isosaxorumamide, stemonine bisdehydroneostemoninine, obtained from aforementioned late‐stage derivatizations. A novel visible‐light photoredox‐catalyzed formal [3+2] cycloaddition was also developed, which offers a valuable tool for accessing oxaspirobutenolide related scaffolds.

Language: Английский

---

Straightforward Synthesis of Spirocyclic Tetrahydrofurans by a Reductive MCR/Iodoetherification Sequence

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(7), P. 4971 - 4980

Published: March 21, 2022

A straightforward and modular sequence for the synthesis of substituted spirocyclic tetrahydrofurans is described. The strategy relies on a reductive cobalt-catalyzed three-component reaction between cyclic ketone, an acrylate, vinylic bromide followed by intramolecular iodoetherification resulting γ-hydroxyalkene. Some functional group interconversions allowed preparation more varied compounds.

Language: Английский

---

Direct synthesis of fluorene-based spirolactones through a BF₃-promoted spiroannulation of α-keto acids and o-alkynylbiaryls

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 10(2), P. 363 - 368

Published: Nov. 24, 2022

A novel and practical approach to fluorene-based spirolactones has been described via BF 3 -promoted spiroannulation of α-keto acids o -alkynyl biaryls. This metal-free cascade reaction provides a wide range products in good excellent yields.

Language: Английский

---