Umpolung of Imines Enables Catalytic Asymmetric Regio‐reversed [3+2] Cycloadditions of Iminoesters with Nitroolefins

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(20), С. 5888 - 5892

Опубликована: Март 31, 2018

Abstract A copper‐catalyzed regio‐reversed asymmetric [3+2] cycloaddition of iminoesters with nitroolefins is disclosed for the first time. This method enables facile synthesis polysubstituted chiral pyrrolidines bearing at least one quaternary center in high yields excellent regio‐, diastereo‐, and enantioselectivity. The application P,S ligands unique effect α‐aryl groups on are key to success this method. practicality versatility reaction also demonstrated.

Язык: Английский

---

Reductive Cross-Coupling of Aldehydes and Imines Mediated by Visible Light Photoredox Catalysis

Organic Letters, Год журнала: 2018, Номер 21(1), С. 27 - 31

Опубликована: Ноя. 28, 2018

Under photoredox catalysis conditions, the conventional electrophilic reactivity of ketimines is inverted to generate nucleophilic species. As a result, chemoselective cross-electrophile couplings between aldehydes and are achieved via umpolung furnish amino alcohols (44 examples with good excellent yields). To illustrate utility alcohol products, 1,2-dihydroindol-3-one-based fluorophores easily synthesized using coupling products. Finally, plausible reaction pathway discussed.

Язык: Английский

---

Copper-Catalyzed Borylative Multicomponent Synthesis of Quaternary α-Amino Esters

ACS Catalysis, Год журнала: 2019, Номер 9(3), С. 1655 - 1661

Опубликована: Янв. 9, 2019

Copper-catalyzed coupling of readily available ketiminoesters, allenes, and a diboron affords densely functionalized quaternary α-amino esters bearing adjacent stereocenters versatile vinyl boronate motifs. The method utilizes commercially copper(I) catalyst, operates at ambient temperature, features catalytic allyl cupration ketiminoesters.

Язык: Английский

---

Synergistic Pd/Cu catalysis for stereoselective allylation of vinylethylene carbonates with glycine iminoesters: Enantioselective access to diverse trisubstituted allylic amino acid derivatives

Green Synthesis and Catalysis, Год журнала: 2021, Номер 2(2), С. 228 - 232

Опубликована: Апрель 19, 2021

We reported a synergistic Pd/Cu catalyzed enantioselective decarboxylative allylation of vinylethylene carbonates with glycine iminoesters, which provides facile access to non-proteinogenic diverse trisubstituted allylic amino acid derivatives in high yields, exclusive regioselectivities and excellent stereoselectivities. This reaction tolerates wide range γ β-aryl substituted either electron-donating or electron-withdrawing groups. Significantly, this method was proven be sufficient the gram scale synthesis chiral while retaining enantioselectivity geometric control.

Язык: Английский

---

Pd/Cu dual catalysis: highly enantioselective access to α-substituted α-amino acids and α-amino amides

Chemical Communications, Год журнала: 2017, Номер 54(6), С. 599 - 602

Опубликована: Дек. 11, 2017

The asymmetric allylation of glycine iminoesters has been accomplished through a synergistic Pd/Cu catalyst system, affording range α-substituted α-amino acids in high yields and with excellent enantioselectivities (88 → 99% ee). introduction Cu-P,N-metallocenyl complex-activated iminoester to the chiral palladium-catalyzed allylic process is crucial owing its reactivity enantioselectivities. Importantly, this dual catalysis strategy can be used for alkylation prochiral amide derivatives, which could further utilized synthesize biologically important vicinal diamines.

Язык: Английский

---

Iridium‐Catalyzed Asymmetric Allylic Aromatization Reaction

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(31), С. 10493 - 10499

Опубликована: Май 13, 2019

Abstract Described herein is an asymmetric allylic aromatization (AAAr) strategy that employs readily accessible equivalents of benzylic nucleophiles in iridium‐catalyzed substitution reactions with the concomitant formation aromatic rings by aromatization. The optimized reaction conditions involving a catalyst derived from commercially available iridium precursor and Carreira ligand are compatible 4‐ or 5‐methyloxazoles, 5‐methylthiazoles, 5‐methylfurans, 2‐ 3‐methylbenzofurans, 3‐methylbenzothiophene, 3‐methylindole, 1‐methylnaphthalene, methylbenzene. This provides straightforward accesses to valuable heterocyclic compounds, bearing homobenzylic stereogenic center, enantiopure form would be difficult access otherwise. versatility was showcased further elaboration products into useful building blocks drug analogue.

Язык: Английский

---

Catalytic Asymmetric Synthesis of α-Tetrasubstituted α-Trifluoromethyl Homoallylic Amines by Ir-Catalyzed Umpolung Allylation of Imines

Organic Letters, Год журнала: 2019, Номер 21(17), С. 6951 - 6956

Опубликована: Авг. 16, 2019

A general and mild method to prepare enantioenriched α-trifluoromethyl, α-stereogenic homoallylic amines is established. This reaction, which involves an Ir-catalyzed umpolung allylation of imines a 2-aza-Cope rearrangement cascade, could yield both tetrasubstituted trisubstituted stereocenters. transformation employs readily available starting materials displays broad substrate scope. The isolation structural determination reaction intermediates revealed factors critical for the efficiency stereoselectivity this transformation.

Язык: Английский

---

Enantioselective and Diastereodivergent Access to α‐Substituted α‐Amino Acids via Dual Iridium and Copper Catalysis

Advanced Synthesis & Catalysis, Год журнала: 2018, Номер 361(5), С. 1130 - 1139

Опубликована: Окт. 24, 2018

Abstract The work reported within this paper describes an example of the application bimetallic catalysts system in allylic substitution reactions. development new nucleophiles and control enantio‐ diastereoselectivity are main research topics area. An improvement reactivity has been realized for dual Ir/Cu catalyzed alkylation inactive prochiral nucleophiles, under mild reaction conditions. Furthermore, choice metallacyclic iridium complex chiral Cu‐Phox combination allows access to all four stereoisomers from same starting materials with excellent enantioselectivity (up >99% ee >20:1 dr). Significantly, method provides a stereodivergent 2‐amino‐3‐methylpent‐4‐acid ester, important fragment synthesis Halipeptin A. magnified image

Язык: Английский

---

Palladium-catalyzed asymmetric allylic C-H alkylation of 1,4-dienes and glycine Schiff bases

Science China Chemistry, Год журнала: 2020, Номер 63(4), С. 454 - 459

Опубликована: Март 13, 2020

Язык: Английский

---

Synergistic Catalysis between a Dipeptide Phosphonium Salt and a Metal‐Based Lewis Acid for Asymmetric Synthesis ofN‐Bridged [3.2.1] Ring Systems

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(38)

Опубликована: Июнь 29, 2022

Abstract We present an unprecedented synergic catalytic route for the asymmetric construction of fluorinated N ‐bridged [3.2.1] cyclic members tropane family via a bifunctional phosphonium salt/silver co‐catalyzed cyclization process. A broad variety substrates bearing assortment functional groups are compatible with this method, providing targeted compounds seven‐membered ring and four contiguous stereocenters in high yields excellent stereoselectivities. The gram‐scale preparations, facile elaborations preliminary biological activities products demonstrate application potential. Moreover, both experimental computational mechanistic studies revealed that proceeded “sandwich” reaction model multiple weak‐bond cooperative activations. Insights gained from our expected to advance general efforts towards synthesis challenging chiral heterocyclic molecules.

Язык: Английский

---