Divergent Total Syntheses of (+)‐Vulgarisins A–E

Angewandte Chemie, Год журнала: 2023, Номер 135(23)

Опубликована: Апрель 10, 2023

Abstract The asymmetric total syntheses of (+)‐vulgarisins A–E, which share a rare and highly oxygenated [5‐6‐4‐5] tetracyclic core structure that were isolated from P. vulgaris Linn., have been described for the first time in divergent manner. Key transformations include: 1) catalytic intramolecular cyclopropanation to forge A ring bearing desired stereochemistry at C14; 2) one‐pot borylation/conjugate addition process creation C1−C11 bond; 3) Wolff contraction assemble bicyclo[3.2.0]heptane subunit (CD rings); 4) stereocontrolled pinacol cyclization construction central B natural products.

Язык: Английский

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Microwave irradiated Heck reactions for synthesis of fused benzoxocinoquinolines by nano-sized zinc Aluminate: A green protocol

Materials Today Proceedings, Год журнала: 2023, Номер 92, С. 906 - 911

Опубликована: Янв. 1, 2023

Язык: Английский

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Ni-Catalyzed Enantioselective Intramolecular Mizoroki–Heck Reaction for the Synthesis of Phenanthridinone Derivatives

The Journal of Organic Chemistry, Год журнала: 2023, Номер 88(13), С. 8203 - 8226

Опубликована: Июнь 15, 2023

A Ni-catalyzed enantioselective intramolecular Mizoroki-Heck reaction has been developed to transform symmetrical 1,4-cyclohexadienes with attached aryl halides into phenanthridinone analogues containing quaternary stereocenters. Herein, we report important advances in optimization enabling control of unwanted proto-dehalogenation and alkene reduction side products. Moreover, this approach provides direct access six-membered ring heterocyclic systems bearing all-carbon stereocenters, which have much more challenging form enantioselectively nickel-catalyzed Heck reactions. wide range substrates were demonstrated work good excellent yields. Good enantioselectivity was using a new synthesized chiral iQuinox-type bidentate ligand (L27). The sustainability, low price nickel catalysts, significantly faster rate (1 h) versus that recently reported palladium-catalyzed (20 make process an attractive alternative.

Язык: Английский

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Nickel-Catalyzed Heck Reaction

SynOpen, Год журнала: 2023, Номер 07(01), С. 114 - 116

Опубликована: Март 1, 2023

Abstract

Язык: Английский

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Controlling Reactivity and Selectivity in the Mizoroki-Heck Reaction: High Throughput Evaluation of 1,5-Diaza-3,7-diphosphacyclooctane Ligands

Опубликована: Дек. 22, 2023

We report a high throughput evaluation of the Mizoroki-Heck reaction diverse olefin coupling partners. Comparison different ligands revealed 1,5-diaza-3,7-diphosphacyclooctane (P2N2) scaffold to be more broadly applicable than common ‘gold standard’ ligands, demonstrating that this family readily accessible diphosphines have unrecognized potential in organic synthesis. In particular, two structurally related P2N2 were identified enable regiodivergent arylation styrenes. By simply altering phosphorus substituent from phenyl tert-butyl group, both linear and branched products can obtained regioisomeric ratios. Experimental computational mechanistic studies performed further probe origin selectivity, which suggests coordinate metal similar manner, but rigid positioning forces contact with incoming pi-pi interaction (for P-Ph ligands) or steric clash P-tBu ligands), dictating regiocontrol

Язык: Английский

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Pyridine Functionalized Polystyrene Supported Cobalt Superfine Fibers as an Efficient and Recyclable Catalyst for Heck Reactions

Fibers and Polymers, Год журнала: 2024, Номер 25(3), С. 797 - 805

Опубликована: Фев. 15, 2024

Язык: Английский

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The Development of Ferrocene and Vinyl Pyridine Containing Triphenylamine-based Dyes for Integrated Light Harvesting Devices Involving Dye-sensitized Solar Cell Technology

Опубликована: Июнь 18, 2024

<p>As new solar cell technologies are developed, their adoption would likely be enhanced through novel applications. To this end, thesis explores the development of two types organic dyes for integrated devices that incorporate dye sensitized (DSSC) technology; notably, smart windows and motion sensing. DSSCs have advantage over other in they optically transparent can implemented into various design concepts including bifacial or coatings. Because powerhouse DSSC is molecular nature, also function diffuse light, which means employed thatcould used any lightcondition. Furthermore, sensitizer tuned further desired application. examines different families After a brief generic introduction Chapter 1, 2 visits idea using ferrocene (Fc) as an additional redox-active donor component to dye. Fc known its redox robustness, goal functionality added enhance stability photo-oxidized dye, such these corresponding could devices, supercapacitor windows. examining structure-property relationships family, very poor efficiencies will prevent deployment, fully articulated 2. 3 potential appending vinyl pyridinium electron withdrawing groups architecture (analogous Fc-derivatives 2). Ultimately, chapter was examine where transformed motion-sensing In theory, achieved by shunt-like dyes, specific wavelengths decrease performance when absorbing diffuse, long light. Unfortunately, synthetic limitations prevented completion target but precursors examined Owing uniqueness each application, Chapters extensive introduction. Further context found at end with conclusions future work.</p>

Язык: Английский

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Aerobic Oxidative Coupling of 2-Naphthols Catalyzed by Flame-Made Vox /T-Zro2: Effect of Metal Oxide Support and Vox Content on Catalytic Activity

Опубликована: Янв. 1, 2023

Oxidative coupling of 2-naphthols to 1,1'-bi-2-naphthols in air at 50 °C was conducted by using VOx supported on metal oxides prepared flame spray pyrolysis. Among the tested catalysts, highest yield (91%) achieved VOx/t-ZrO2 (containing 7.8 wt% as V2O5). The catalytic activity decreased content increased. At lower content, catalyst primarily consisted monovanadate species with square pyramidal coordination. As increased, fraction monovanadates decreased, whereas that polyvanadates H2 temperature-programmed reduction measurements revealed exhibited temperatures than polyvanadates. Therefore, our results suggest highly reactive t-ZrO2 are active sites for reaction.

Язык: Английский

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Synthesis and Spectroscopic Characterization of the Four Complete Series [(C₅X_nH_5‐n)Fe(CO)₂R] (X= Cl, Br; R= Me, Ph; n= 1–5). Molecular and Crystal Structures of [(C₅X₅)Fe(CO)₂R]

ChemistrySelect, Год журнала: 2022, Номер 7(33)

Опубликована: Сен. 1, 2022

Abstract The complete series of chloro‐ and bromo‐cyclopentadienyl carbonyl complexes [(C 5 X n H 5‐n )Fe(CO) 2 R] (n=1–5, R=Me, Ph) could be prepared from the unsubstituted parent compounds via a sequence lithiations electrophilic halogenations. All four pentahaloyclopentadienyl were studied by X‐ray diffraction show an interplay weak intermolecular X…X, X…O X…H interactions.

Язык: Английский

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