Enantioselective Formation of Quaternary Centers by Allylic Alkylation with First-Row Transition-Metal Catalysts

Chemical Reviews, Год журнала: 2021, Номер 121(7), С. 4084 - 4099

Опубликована: Фев. 11, 2021

Asymmetric allylic alkylation mediated by transition metals provides an efficient strategy to form quaternary stereogenic centers. While this transformation is dominated the use of second- and third-row (e.g., Pd, Rh, Ir), recent developments have revealed potential first-row metals, which provide not only a less expensive potentially equally alternative but also new mechanistic possibilities. This review summarizes examples for assembly stereocenters using prochiral substrates hard, achiral nucleophiles in presence copper complexes highlights complementary approaches with soft, catalyzed chiral cobalt nickel complexes.

Язык: Английский

---

Catalytic Enantioselective Alkylation of Prochiral Enolates

Chemical Reviews, Год журнала: 2021, Номер 121(15), С. 9196 - 9242

Опубликована: Июль 26, 2021

The asymmetric alkylation of enolates is a particularly versatile method for the construction α-stereogenic carbonyl motifs, which are ubiquitous in synthetic chemistry. Over past several decades, focus has shifted to development new catalytic methods that depart from classical stoichiometric stereoinduction strategies (e.g., chiral auxiliaries, alkali metal amide bases, electrophiles, etc.). In this way, enantioselective prochiral greatly improves step- and redox-economy process, addition enhancing scope selectivity these reactions. review, we summarize origin advancement enolate methods, with directed emphasis on union nucleophiles carbon-centered electrophiles derivatives. Hence, transformative developments each distinct class nucleophile ketone enolates, ester etc.) presented modular format highlight state-of-the-art current limitations area.

Язык: Английский

---

Asymmetric Redox Allylic Alkylation to Access 3,3′‐Disubstituted Oxindoles Enabled by Ni/NHC Cooperative Catalysis

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(22)

Опубликована: Март 3, 2022

The feasibility of cooperative catalysis between chiral N-heterocyclic carbenes and nickel in asymmetric reactions has been demonstrated convincingly. high efficiency this catalytic system enables the allylic alkylation isatin-derived enals with carbonates [3+3] annulation racemic vinyl epoxides to provide straightforward access highly enantioenriched 3,3'-disubstituted oxindoles. great practicality method organic synthesis showcased by facile product modification enantioselective key building block (-)-debromoflustramine B.

Язык: Английский

---

Brønsted acid and Pd–PHOX dual-catalysed enantioselective addition of activated C-pronucleophiles to internal dienes

Chemical Science, Год журнала: 2019, Номер 10(19), С. 5176 - 5182

Опубликована: Янв. 1, 2019

We describe the development of Pd–PHOX-catalysed enantioselective couplings internal dienes with malononitrile and other activated C-pronucleophiles.

Язык: Английский

---

Access to 1,3‐Dinitriles by Enantioselective Auto‐tandem Catalysis: Merging Allylic Cyanation with Asymmetric Hydrocyanation

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(17), С. 6785 - 6789

Опубликована: Фев. 7, 2020

Abstract Enantioselective auto‐tandem catalysis represents a challenging yet highlight attractive topic in the field of asymmetric catalysis. In this context, we describe dual catalytic cycle that merges allylic cyanation and hydrocyanation. The one‐pot conversion broad array alcohols into their corresponding 1,3‐dinitriles proceeds good yield with high enantioselectivity. products are densely functionalized can be easily transformed to chiral diamines, dinitriles, diesters, piperidines. Mechanistic studies clearly support novel sequential cyanation/hydrocyanation pathway.

Язык: Английский

---

Enantioselective Synthesis of Quaternary Carbon Stereocenters by Asymmetric Allylic Alkylation: A Review

Chemistry - An Asian Journal, Год журнала: 2021, Номер 16(14), С. 1864 - 1877

Опубликована: Май 20, 2021

Abstract Quaternary stereocenters are of great importance to the three‐dimensionality and enhanced properties new molecules, but synthetic challenges in creating quaternary greatly hinder their wide use drug discovery, organic material design, natural product synthesis. The asymmetric allylic alkylation (AAA) substrates has proven be a powerful methodology for enantioselective formation structure skeletons bearing single or more carbon centers modern organocatalysis. AAA certain advantages constructing tetrasubstituted stereocenters, including not limited mild reactive conditions, effective reaction rates, functional group introduction, chains length extension. This review outlines key considerations application reactions summarizes recent progress synthesis products containing stereocenters. Meanwhile, detailed discussion such as ligands, scope substrates, transformations general mechanisms is also provided. We hope this could stimulate further advances much broader areas, synthesis, catalysis, C−H activation, symmetrical pharmaceutical chemistry.

Язык: Английский

---

Construction of Vicinal Quaternary Carbon Centers via Cobalt-Catalyzed Asymmetric Reverse Prenylation

Organic Letters, Год журнала: 2019, Номер 21(5), С. 1278 - 1282

Опубликована: Фев. 15, 2019

A highly enantioselective cobalt-catalyzed reverse prenylation of β-ketoester with tertiary allylic carbonate to construct vicinal all-carbon quaternary carbon centers has been developed. By using the cobalt/(S,S)Ph-BPE complex generated in situ zinc reduction, excellent branched linear selectivity (>20:1) and up 92% ee have obtained.

Язык: Английский

---

Enantioselective Divergent Synthesis of C19-Oxo Eburnane Alkaloids via Palladium-Catalyzed Asymmetric Allylic Alkylation of an N-Alkyl-α,β-unsaturated Lactam

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(12), С. 4811 - 4814

Опубликована: Март 8, 2019

The C19-oxo-functionalized eburnane alkaloids display unique chemical structure and interesting biological activity. Herein, we report a divergent enantioselective strategy to access these by use of challenging palladium-catalyzed asymmetric allylic alkylation an N-alkyl-α,β-unsaturated lactam. 19-(S)-OH-Δ14-vincamone (phutdonginin), (−)-19-OH-eburnamine, (+)-19-oxoeburnamine, (+)-19-OH-eburnamonine (1–4) have been concisely synthesized for the first time in 11 13 steps.

Язык: Английский

---

Asymmetric Allylic Alkylation of β-Ketoesters via C–N Bond Cleavage of N-Allyl-N-methylaniline Derivatives Catalyzed by a Nickel–Diphosphine System

ACS Catalysis, Год журнала: 2020, Номер 10(10), С. 5828 - 5839

Опубликована: Апрель 22, 2020

Nickel complexes bearing chiral diphosphine ligands, such as (S)-Tol-MeO-BIPHEP and (S)-H8-BINAP, serve efficient catalysts for asymmetric allylic alkylation (AAA) of β-ketoesters, using amines allyl sources. The reactions proceed with high catalytic activity enantioselectivity. N-Methyl-N-phenyl were indispensable to achieve the activity, enantioselectivity, expand substrate scope 5- 7-membered whose nickel-catalyzed AAA alcohols results in low On basis kinetics a catalyst system made Ni(cod)2 (S)-Tol-MeO-BIPHEP, DFT calculations reaction pathway mediated by an isolated olefin-coordinated nickel–DPPF complex 4b, we propose mechanism where protonation nitrogen atom coordinating amine β-ketoester is key cleaving C–N bond delivering cationic π-allyl nickel(II) intermediate.

Язык: Английский

---

Nickel‐Catalyzed Allylic Substitution Reactions: An Evolving Alternative

European Journal of Inorganic Chemistry, Год журнала: 2021, Номер 2022(2)

Опубликована: Ноя. 9, 2021

Abstract Transition metal‐catalyzed allylic substitution reactions represent versatile transformations in organic synthesis forging C−C and C‐heteroatom bonds. Despite major contributions realized with precious transition metals, earth‐abundant nickel catalysis over the years has emerged as a relative sustainable efficient alternative area of reactions. During last two decades, field witnessed successful accomplishments chemo‐, regio‐ enantioselective conversions affording plethora products through employment Ni‐based methodologies. In this Minireview, most imperative will be discussed special attention for more character unique reactivity Ni, overall process selectivity features functional group tolerance product scope.

Язык: Английский

---