Dearomative [4 + 2] cycloaddition of 3‐nitroindoles with ortho‐amino Morita−Baylis−Hillman carbonates to forge indole‐fused quinolines

Journal of Heterocyclic Chemistry, Год журнала: 2024, Номер 61(3), С. 528 - 537

Опубликована: Янв. 16, 2024

Abstract A dearomative [4 + 2] cycloaddition of 3‐nitroindoles ortho ‐amino Morita−Baylis−Hillman carbonates was established under mild conditions. This method provides an efficient and practical approach for delivering tetrahydro‐5 H ‐indolo[2,3‐ b ]quinolines containing three contiguous stereocenters, two tertiary one quaternary, in high yield (up to 95%) with excellent diastereoselectivity (all cases >25:1 dr ). The potential synthetic applications this strategy were also highlighted by the scale‐up experiment further transformation. Moreover, structure relative configuration cycloadduct unequivocally confirmed single‐crystal X‐ray diffraction.

Язык: Английский

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Catalyst-Controlled Switchable (5 + 4)/(3 + 4) Cycloadditions for the Divergent Synthesis of Pyrazole-Fused Seven- and Nine-Membered Heterocycles

ACS Catalysis, Год журнала: 2023, Номер 13(16), С. 10694 - 10704

Опубликована: Авг. 1, 2023

Developing diversity-oriented synthetic approaches for medium-sized rings is of great interest, and the divergent synthesis with different ring sizes poses a challenging task. In this study, we present catalyst-controlled switchable (5 + 4)/(3 4) cycloaddition strategy seven- nine-membered heterocycles. Utilizing two 4-aminopyridine Lewis base catalysts, pyrazole-fused benzazepines or benzoxazonines can be efficiently assembled from same substrates. These products exhibit good stability without interconversion under reaction conditions elevated temperatures. The origin chemoselectivity was elucidated by means computational studies involving DFT calculations, distortion/interaction analysis, noncovalent interaction analysis.

Язык: Английский

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Iridium-Catalyzed Diastereo- and Enantioselective [4 + 1] Cycloaddition of Hydroxyallyl Anilines with Sulfoxonium Ylides

Organic Letters, Год журнала: 2023, Номер 25(25), С. 4621 - 4626

Опубликована: Июнь 15, 2023

We present here an iridium-catalyzed diastereo- and enantioselective [4 + 1] cycloaddition reaction of hydroxyallyl anilines with sulfoxonium ylides under mild conditions, leading to 3-vinyl indolines in moderate good yields excellent enantioselectivities. Control experiments disclosed a plausible mechanism.

Язык: Английский

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Access to Chiral Tetrahydroquinazolines/1,3-Benzoxazines via Iridium-Catalyzed Asymmetric [4 + 2] Cycloaddition

Organic Letters, Год журнала: 2023, Номер 25(20), С. 3639 - 3643

Опубликована: Май 16, 2023

An iridium-catalyzed asymmetric [4 + 2] cycloaddition of 1,3,5-triazinanes with 2-(1-hydroxyallyl)anilines/2-(1-hydroxyallyl)phenols has been developed, providing a straightforward and efficient approach to wide range tetrahydroquinazolines in good yields excellent enantioselectivities (up >99% ee). Typically, chiral 1,3-benzoxazines, which are challenging substrates cycloaddition, could be obtained via this protocol.

Язык: Английский

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Remote stereocontrol in the (4 + 2) cycloadditions of 1,7-zwitterions: Asymmetric synthesis of multifunctionalized tetrahydroquinoline derivatives

Chinese Chemical Letters, Год журнала: 2023, Номер 35(1), С. 108295 - 108295

Опубликована: Март 5, 2023

Язык: Английский

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Phosphine-catalysed transformations of ortho- and para-quinone methides

Organic & Biomolecular Chemistry, Год журнала: 2023, Номер 21(41), С. 8244 - 8258

Опубликована: Янв. 1, 2023

A powerful and straightforward way to access a variety of oxa-heterocycles N-heterocycles: the phosphine-catalysed transformations o -QM, p -QM aza- -QM.

Язык: Английский

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Asymmetric Catalytic Transformations of Aza‐ortho‐ and Aza‐para‐Quinone Methides

ChemCatChem, Год журнала: 2023, Номер 15(13)

Опубликована: Май 3, 2023

Abstract The catalytic methodologies for the derivatization of aza‐QM have recently appeared in literature and involve organocatalytic organometallic approaches. This review aims at analyzing diverse systems involving chiral NHC carbenes, phosphoric acids, phosphoramidites, phosphine copper palladium catalysis showing its applicability synthesis a away N ‐containing compounds which many cases biological activity.

Язык: Английский

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De novo Synthesis of Chiral 3,4‐DihydroquinazolinesviaOne‐Pot Enantioselective Ugi‐Azide/Cyclization Sequences^†

Chinese Journal of Chemistry, Год журнала: 2024, Номер 42(18), С. 2140 - 2146

Опубликована: Май 7, 2024

Comprehensive Summary Herein, we reported a precise de novo synthesis of chiral 3,4‐dihydroquinazoline frameworks via one‐pot anionic stereogenic‐at‐cobalt(III) complex‐catalyzed enantioselective Ugi‐azide/Pd‐catalyzed cyclization sequence. This powerful protocol involves 5 components and 2 catalytic systems, delivering 3,4‐dihydroquinazolines with excellent enantioselectivities (up to 94% ee). The preliminary antifungal experiments suggest that both Ugi‐adducts have great potential in inhibiting plant pathogens such as Trichoderma viride Fusarium graminearum .

Язык: Английский

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Lewis Base Controlled (4 + 3) and (4 + 2) Annulations of MBH Carbonates with Benzofuran‐derived Azadienes: Access to Highly Substituted Benzofuro[3,2‐b]azepines and Spirotetrahydroquinolines

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(21), С. 4521 - 4527

Опубликована: Авг. 7, 2024

Abstract Catalyst‐controlled switchable (4+3) and (4+2) annulation reactions of Morita–Baylis–Hillman carbonates with benzofuran‐derived azadienes have been established. Employing PCy 3 as the catalyst, reaction could provide a variety synthetically useful benzofuro[3,2‐ b ]azepines in good yields (80–92%) excellent chemo‐ regioselectivities via cycloaddition reactions. Whereas changing catalyst from to DMAP, were switched construct highly substituted spirotetrahydroquinoline scaffolds three sequential stereocenters containing all‐carbon spiro‐quaternary efficiency diastereoselectivities (92–96% all cases>25:1 dr ) annulations. In addition, synthetic utility this method was further showcased by gram‐scale transformations product.

Язык: Английский

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Organocatalytic Regio- and Enantioselective Allylic Alkylation of Indolin-2-imines with MBH Carbonates toward 3-Allylindoles

The Journal of Organic Chemistry, Год журнала: 2023, Номер 88(12), С. 7810 - 7814

Опубликована: Янв. 26, 2023

An organocatalytic asymmetric C3-allylic alkylation of indolone-2-imines with MBH carbonates has been developed for the first time. As opposed to previous reports, an "interrupted" annulation was achieved, affording 3-allylindoles in generally high yields excellent stereoselectivities. The representative scale-up reaction and transformation were examined. A possible mechanism also proposed.

Язык: Английский

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