Asymmetric Cycloaddition and Cyclization Reactions Catalyzed by Chiral N,N′-Dioxide–Metal Complexes

Accounts of Chemical Research, Journal Year: 2017, Volume and Issue: 50(10), P. 2621 - 2631

Published: Oct. 2, 2017

ConspectusCatalytic asymmetric cycloadditions and cascade cyclizations are a major focus for the enantioselective construction of chiral carbo- heterocycles. A number Lewis acids organocatalysts have been designed such reactions. The development broadly applicable catalysts bearing novel backbones to meet demands various applications is an ongoing challenge. Approximately 10 years ago, we introduced group conformationally flexible C2-symmetric N,N′-dioxide amide compounds, which represent new class privileged ligands. coordination four oxygens around central metal generates octahedral tricyclometalated acid catalyst that can carry out In this Account, summarize our recent studies on between dienophiles dienes, dipoles dipolarophiles, catalyzed by N,N′-dioxide–metal complexes. principle, these unique lower LUMO energy electron-deficient 2π components or heterodienes with functional groups via binding modes.With N-Boc-3-alkenyloxindole alkylidene malonate as components, complexes provided excellent catalytic activities inductions variety transformations, including [2 + 1], [3 2], [4 [8 2] cycloadditions. Mechanistically, substrates could be efficiently activated through bidentate coordination. strategy was also useful form polycyclic adducts. Monodentate other α,β-unsubstituted carbonyl compounds centers enabled both normal Diels–Alder reactions inverse-electron-demand hetero-Diels–Alder well additions. Furthermore, aldehydes, ketones, imines well-tolerated afford This includes allowing concise synthesis antimalarial compound KAE609. Asymmetric Michael/cyclization α,β-unsaturated pyrazolamides gave efficient access drugs (−)-paroxetine (R)-thiazesim. formal donor–acceptor epoxides aziridines enantioselectively series five-membered oxo- aza-heterocycles. reaction cyclopropane diketones showed unprecedented reactivities route dihydropyrrole benzimidazole derivatives.General models emerged from knowledge absolute configurations products several X-ray crystal structures catalysts. field chirality created center, bonding one two reactants establishes perfect template generation target Representative examples used demonstrate how substructures ligands affect stereoselectivity salts impact reactivity. These results reveal importance tunability compatibility precursors achieving high stereoinduction activity.

Language: Английский

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Lewis Acid Catalyzed Dynamic Kinetic Asymmetric Transformation of Racemic N-Sulfonylaziridines

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(49), P. 17211 - 17217

Published: Nov. 13, 2018

The first Lewis acid catalyzed stereoconvergent transformation of racemic 2-(hetero)aryl-N-sulfonylaziridines via C–N bond cleavage with nucleophiles is presented. This includes the [3 + 2] annulations (hetero)aromatic aldehydes and 1,3-disubstituted indoles, asymmetric Friedel–Crafts type reaction electron-rich (hetero)arenes, aminolysis amines, providing facile access to chiral 1,3-isoxazolidines, pyrroloindolines, 2-(hetero)arylphenethylamines, vicinal diamines. method features a simple cheaply available complex Cu(I)–chiral BINAP catalyst, excellent yield high diastereo- enantioselectivities, mild conditions. A mechanism involving I dynamic kinetic transformations (DyKATs) aziridines proposed based on results control experiments.

Language: Английский

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Gold/Lewis Acid Catalyzed Cycloisomerization/Diastereoselective [3 + 2] Cycloaddition Cascade: Synthesis of Diverse Nitrogen-Containing Spiro Heterocycles

Organic Letters, Journal Year: 2016, Volume and Issue: 18(18), P. 4614 - 4617

Published: Aug. 30, 2016

A novel early and late transition-metal relay catalysis has been developed by combining a gold-catalyzed cycloisomerization Yb(OTf)3-catalyzed diastereoselective [3 + 2] cycloaddition with aziridines in selective C-C bond cleavage mode. Various biologically significant complex nitrogen-containing spiro heterocycles were rapidly constructed from readily available starting materials under mild conditions.

Language: Английский

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Catalytic asymmetric hydroxylative dearomatization of 2-naphthols: synthesis of lacinilene derivatives

Chemical Science, Journal Year: 2017, Volume and Issue: 8(9), P. 6645 - 6649

Published: Jan. 1, 2017

An enantioselective hydroxylative dearomatization of 2-naphthols with oxaziridines has been accomplished using a N,N'-dioxide-scandium(iii) complex catalyst. Various substituted ortho-quinols could be obtained in high yields (up to 99%) and enantioselectivities 95 : 5 er). This methodology applied the synthesis bioactive lacinilenes gram-scale reaction. Based on experimental investigations previous work, possible catalytic model was proposed.

Language: Английский

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Recent developments in enantioselective lanthanide-catalyzed transformations

Coordination Chemistry Reviews, Journal Year: 2017, Volume and Issue: 336, P. 96 - 151

Published: Feb. 3, 2017

Language: Английский

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Enantioselective Synthesis of N−H‐Free 1,5‐Benzothiazepines

Chemistry - A European Journal, Journal Year: 2016, Volume and Issue: 23(3), P. 554 - 557

Published: Nov. 16, 2016

An enantioselective sulfa-Michael-cyclization reaction was developed for the synthesis of 1,5-benzothiazepines with versatile pharmacological activities. The between 2-aminothiophenol and α,β-unsaturated pyrazoleamides gave direct access to N-H-free in presence a chiral N,N'-dioxide/Yb(OTf)3 complex. Excellent enantioselectivities (up 96 % ee) high yields 99 %) were obtained broad range substrates under mild conditions. This method provided facile approach antidepressant drug (R)-(-)-Thiazesim.

Language: Английский

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Enantioselective Formal [3+2] Cycloaddition of Epoxides with Imines under Brønsted Base Catalysis: Synthesis of 1,3‐Oxazolidines with Quaternary Stereogenic Center

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(21), P. 6299 - 6303

Published: April 12, 2018

Abstract The formal [3+2] cycloaddition of epoxides and unsaturated compounds is a powerful methodology for the synthesis densely functionalized five‐membered heterocyclic containing oxygen. Described novel enantioselective under Brønsted base catalysis. bis(guanidino)iminophosphorane as chiral organosuperbase catalyst enabled reaction β , γ ‐epoxysulfones with imines, owing to its strong basicity high stereocontrolling ability, provide enantioenriched 1,3‐oxazolidines having two stereogenic centers, including quaternary one, in highly diastereo‐ manner.

Language: Английский

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Catalytic Michael/Ring‐Closure Reaction of α,β‐Unsaturated Pyrazoleamides with Amidomalonates: Asymmetric Synthesis of (−)‐Paroxetine

Chemistry - A European Journal, Journal Year: 2016, Volume and Issue: 22(42), P. 15119 - 15124

Published: Aug. 31, 2016

A highly enantioselective tandem Michael/ring-closure reaction of α,β-unsaturated pyrazoleamides and amidomalonates has been accomplished in the presence a chiral N,N'-dioxide-Yb(OTf)3 complex (Tf: trifluoromethanesulfonyl) to give various substituted glutarimides with high yields diastereo- enantioselectivities. Moreover, this methodology could be used for gram-scale manipulation was successfully applied synthesis (-)-paroxetine. Further nonlinear HRMS studies revealed that real catalytically active species monomeric L-PMe2 -Yb3+ complex. plausible transition state proposed explain origin asymmetric induction.

Language: Английский

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Asymmetric [3 + 2] Cycloaddition of 2,2′-Diester Aziridines To Synthesize Pyrrolidine Derivatives

ACS Catalysis, Journal Year: 2017, Volume and Issue: 7(6), P. 3934 - 3939

Published: May 4, 2017

A highly diastereo- and enantioselective [3 + 2] cycloaddition of 2,2′-diester aziridines with 3,4-dihydropyran derivatives acyclic enol ethers has been established. Various optically active octahydropyrano[2,3-c]pyrrole 3-methoxypyrrolidine were generated in moderate to high yields (up 94%) good stereoselectivities (>19:1 dr, up 95.5:4.5 er). The methodology was also applied the diastereoselective synthesis d-galactal derivatives. absolute configuration octahydropyrano[2,3-c]pyrroles showed that reactions using 6-alkyl-substituted ones as substrates gave reversed diastereoselection final cyclization step.

Language: Английский

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Regioselective Brønsted Acid Catalyzed Ring Opening of Aziridines by Phenols and Thiophenols; A Gateway to Access Functionalized Indolines, Indoles, Benzothiazines, Dihydrobenzo-thiazines, Benzo-oxazines and Benzochromenes

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(27), P. 5653 - 5664

Published: Jan. 1, 2024

A TfOH-catalyzed regioselective ring opening of aziridines by phenols and thiophenols have been reported. Further synthetic transformations lead to access a range useful heterocycles.

Language: Английский

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