Organic Synthesis Using Nitroxides

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(16), P. 10302 - 10380

Published: Aug. 14, 2023

Nitroxides, also known as nitroxyl radicals, are long-lived or stable radicals with the general structure R1R2N–O•. The spin distribution over nitroxide N and O atoms contributes to thermodynamic stability of these radicals. presence bulky N-substituents R1 R2 prevents radical dimerization, ensuring their kinetic stability. Despite reactivity toward various transient C some nitroxides can be easily stored under air at room temperature. Furthermore, oxidized oxoammonium salts (R1R2N═O+) reduced anions (R1R2N–O–), enabling them act valuable oxidants reductants depending on oxidation state. Therefore, they exhibit interesting across all three states. Due fascinating properties, find extensive applications in diverse fields such biochemistry, medicinal chemistry, materials science, organic synthesis. This review focuses versatile For use other important fields, we will refer several articles. introductory part provides a brief overview history chemistry. Subsequently, key methods for preparing discussed, followed by an examination structural diversity physical properties. main portion this is dedicated reactions, wherein parent corresponding serve active species. It demonstrated that functional groups (such alcohols, amines, enolates, alkanes among others) efficiently oxidized. These oxidations carried out using catalysts combination stoichiometric terminal oxidants. By reducing anions, become effective reagents intriguing Nitroxides possess ability selectively react making useful terminating cascade reactions forming alkoxyamines. Depending structure, alkoxyamines weak C–O bonds, allowing thermal generation through reversible bond cleavage. Such thermally generated participate transformations, discussed end review. application strategy natural product synthesis presented.

Language: Английский

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Total Synthesis of (±)- and (−)-Daphnillonin B

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(20), P. 10998 - 11004

Published: May 11, 2023

The first total synthesis of (±)- and (-)-daphnillonin B, a daphnicyclidin-type alkaloid with new [7-6-5-7-5-5] A/B/C/D/E/F hexacyclic core, has been achieved. [6-5-7] B/C/D ring system was efficiently diastereoselectively constructed via mild type I intramolecular [5+2] cycloaddition, followed by Grubbs II catalyst-catalyzed radical cyclization. [5-5] fused E/F synthesized diastereoselective Pauson-Khand reaction. Notably, the synthetically challenging core reassembled unique Wagner-Meerwein-type rearrangement from [6-6-5-7-5-5] framework found in calyciphylline A-type Daphniphyllum alkaloids.

Language: Английский

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Enantioselective Total Synthesis of (−)-Daphenylline

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(2), P. 1262 - 1268

Published: Jan. 5, 2024

A concise enantioselective total synthesis of (−)-daphenylline, a hexacyclic Daphniphyllum alkaloid with unique benzene ring, was achieved in 14 steps. The commences two chiral stereocenters, C2 and C18, readily installed via Carreira's Ir/amine dual-catalyzed allylation. allylic bridgehead amine 6 rapidly prepared through Wickens' photoredox-catalyzed hydrocarboxylation olefin CuBr2-catalyzed α-amination ketone. tetracycle 4 formed Pd-catalyzed reductive Heck reaction or, more concisely, by Krische's Rh-catalyzed 1,6-enyne cyclization. In this synthesis, newly reported used twice, Friedel–Crafts acylation thrice.

Language: Английский

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Forging the Tetracyclic Core Framework of Daphlongamine B Enabled by a Peripheral Derivation of the Aza-Angular Triquinane Strategy

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 19, 2025

A synthetic route to the highly functionalized tetracyclic core framework of daphlongamine B is described. Key features strategy involve an oxidative dearomatization-induced [4+2] cycloaddition, a di-π-methane rearrangement, and ring-closing metathesis reaction. Our approach enables reliable construction fully elaborated precursor, which, in turn, provides valuable functional handles for further elaboration target molecule.

Language: Английский

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Construction of an All-Bridge Carbon-Oxidized 2-Azaadamantane Skeleton and Synthesis of Two Energetic Derivatives

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 24, 2025

The construction of an all-bridge-oxygenated (hetero)adamantane skeleton is a long-standing challenge. Herein, all-bridge carbon-oxidized 2-azaadamantane skeleton, 6,9,10-trimethoxy-2-azaadamantane-4,8-diol, was constructed via eight-step synthetic route from 9-hydroxybicyclo[3.3.1]nonane-2,6-dione with overall yield 45%. obtained derived into two novel high-performance energetic compounds. Among them, 2,9,9,10,10-pentanitro-2-azaadamantane-4,6,8-triyl trinitrate the first example that possesses eight explosophoric groups on adamantane skeleton.

Language: Английский

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Recent Progress in the Total Synthesis of Daphniphyllum Alkaloids

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(3), P. 866 - 866

Published: Jan. 1, 2025

Language: Английский

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Synthetic Study of Kuroshine Alkaloids

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(3), P. 977 - 977

Published: Jan. 1, 2025

Language: Английский

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Synthesis of the AB Ring System of Daphniphyllum Alkaloid Daphniglaucin C

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(3), P. 925 - 925

Published: Jan. 1, 2025

Language: Английский

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Insecticidal Activity of Monoterpenoids Against Sitophilus zeamais Motschulsky and Tribolium castaneum Herbst: Preliminary Structure–Activity Relationship Study

International Journal of Molecular Sciences, Journal Year: 2025, Volume and Issue: 26(7), P. 3407 - 3407

Published: April 5, 2025

To contribute to the search for effective substances in pest control, this study describes fumigant and contact toxicity against Tribolium castaneum Sitophilus zeamais of four essential oils (EOs) some their major chemical constituents. The EOs from Tagetes zypaquirensis, Anethum graveolens, Satureja viminea Minthostachys mollis were obtained by steam distillation chemically characterized using GC-MS. In development research, monoterpenoids isolated EOs, others purchased commercially, synthesized most active present EOs. main components dill ether (28.56%), α-phellandrene (25.78%) carvone (23.67%) A. piperitone oxide (30.40%) pulegone (25.91%) M. mollis, (37.40%) p-menth-3-en-8-ol (11.83%) S. viminea, dihydrotagetone (32.13%), myrcene epoxide (19.64%) β-myrcene (5.30%) T. zypaquirensis. results highlight action (LC50) (LD50) EO (LC50 4.8 µL/L air LD50 6.5 µg/insect) 7.0 5.81 µg/insect). Among constituents evaluated, R-carvone 2, 5 R-pulegone 6 stand out insecticidal potential between 3.0 42.4 µL/L, while 14.9 24.6 2.2 13.1 Preliminary structure-activity analysis suggests that presence carbonyl group with conjugated double bonds cyclic monoterpenes is important exhibited.

Language: Английский

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Total Synthesis of Daphniphyllum Alkaloids: (+)-Daphlongamine E, (+)-Calyciphylline R, and (–)-10-Deoxydaphnipaxianine A

Synthesis, Journal Year: 2024, Volume and Issue: 56(08), P. 1273 - 1284

Published: Jan. 12, 2024

Abstract Here, we wish to describe our detailed efforts in the total synthesis of three calyciphylline A-type alkaloids, namely (+)-daphlongamine E, (+)-calyciphylline R, and (–)-10-deoxydaphnipaxianine A. Important steps approach include a Pt-catalyzed nitrile hydration, Babler–Dauben rearrangement, novel selective amide reduction tactic, an oxidative Nazarov cyclization via unfunctionalized tertiary divinyl carbinol (TDC).

Language: Английский

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