P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(14), P. 8657 - 8739

Published: July 2, 2024

Chiral phosphorus ligands play a crucial role in asymmetric catalysis for the efficient synthesis of useful optically active compounds. They are largely categorized into two classes: backbone chirality and P-stereogenic ligands. Most reported belong to former class. Privileged ones such as BINAP DuPhos frequently employed wide range catalytic transformations. In contrast, latter class has remained small family many years mainly because their synthetic difficulty. The late 1990s saw emergence novel with superior enantioinduction ability Rh-catalyzed hydrogenation reactions. Since then, numerous have been synthesized used This Review summarizes thus far, including stereochemical electronic properties that afford high excellent enantioselectivities. Examples reactions use this described together applications construction key intermediates natural products therapeutic agents. literature covered dates back 1968 up until December 2023, centering on studies published later years.

Language: Английский

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Palladium(0) π-Lewis Base Catalysis: Concept and Development

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(10), P. 6422 - 6437

Published: March 1, 2024

The development of a new catalytic strategy plays vital role in modern organic chemistry since it permits bond formation an unprecedented and more efficient manner. Although the application preformed metal complexes as π-base-activated reagents have enabled diverse transformations elegantly, concept by directly utilizing transition metals π-Lewis base catalysts remain underdeveloped, especially field asymmetric catalysis. Here, we outline our perspective on discovery palladium(0) catalyst, which is capable increasing highest occupied molecular orbital (HOMO) energy both electron-neutral electron-deficient 1,3-dienes 1,3-enynes upon flexible η2-complexes formed situ resultant π-backdonation. Thus, fruitful carbon–carbon-forming reactions with electrophiles can be achieved enantioselectively vinylogous addition pattern, conceptually different from classical oxidative cyclization mechanism. Emphasis will given to mechanism elucidation, features, reaction design together further this emerging field.

Language: Английский

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Stereodivergent access to non-natural α-amino acids via enantio- and Z / E -selective catalysis

Science, Journal Year: 2024, Volume and Issue: 385(6712), P. 972 - 979

Published: Aug. 29, 2024

The precise control of

Language: Английский

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Palladium‐Catalyzed Inverse and Normal Dehydrogenative Aza‐Morita–Baylis–Hillman Reactions with γ,δ‐Unsaturated Compounds

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(23)

Published: April 3, 2023

σ-Lewis base-catalyzed regio- and enantioselective aza-Morita-Baylis-Hillman (MBH) reaction of α,β,γ,δ-unsaturated systems remains a challenge due to the intrinsic covalent activation mode. Here we demonstrate that Pd0 complex can mediate dehydrogenative γ,δ-unsaturated compounds give corresponding electron-poor dienes, which further undergo δ-regioselective umpolung Friedel-Crafts-type addition imines via auto-tandem -π-Lewis base catalysis. After β-H elimination in situ formed PdII -complexes, unprecedented chemically inverse aza-MBH-type adducts are finally furnished with fair outstanding enantioselectivity, diversity functional groups both ketimine aldimine acceptors be well tolerated. Moreover, switchable α-regioselective normal also realized by tuning catalytic conditions, whereas moderate good enantioselectivity low excellent Z/E-selectivity is attained.

Language: Английский

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Enantioselective Cross-[4 + 2]-Cycloaddition/Decarboxylation of 2-Pyrones by Cooperative Catalysis of the Pd(0)/NHC Complex and Chiral Phosphoric Acid

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(10), P. 6936 - 6946

Published: Feb. 28, 2024

Here, we describe a cooperative Pd(0)/chiral phosphoric acid catalytic system that allows us to realize the first chemo-, regio-, and enantioselective sequential cross-[4 + 2]-cycloaddition/decarboxylation reaction between 2-pyrones unactivated acyclic 1,3-dienes. The key success of this transformation is utilization an achiral N-heterocyclic carbene (NHC) as ligand newly developed chiral cocatalyst. Experimental investigations computational studies support idea Pd(0)/NHC complex acts π-Lewis base increase nucleophilicity 1,3-dienes via η2 coordination, while simultaneously increases electrophilicity by hydrogen bonding. By synergistic catalysis, 2]-cycloaddition decarboxylation proceeds efficiently, enabling preparation wide range vinyl-substituted 1,3-cyclohexadienes in good yields enantioselectivities. synthetic utility demonstrated transformations product various valuable six-membered carbocycles.

Language: Английский

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Recent advances in ligand-enabled palladium-catalyzed divergent synthesis

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 22(1), P. 37 - 54

Published: Nov. 27, 2023

Developing efficient and straightforward strategies to rapidly construct structurally distinct diverse organic molecules is one of the most fundamental tasks in synthesis, drug discovery materials science. In recent years, divergent synthesis functional from same starting has attracted significant attention been recognized as an powerful strategy. To achieve this objective, proper adjustment reaction conditions, such catalysts, solvents, ligands, etc., required. review, we summarized efforts chemo-, regio- stereodivergent reactions involving acyclic cyclic systems catalyzed by palladium complexes. Meanwhile, types, including carbonylative reactions, coupling cycloaddition well probable mechanism have also highlighted detail.

Language: Английский

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Catalysis and Synthesis Enabled by P-Chiral Dihydrobenzooxaphosphole Ligands

Organic Process Research & Development, Journal Year: 2024, Volume and Issue: 28(4), P. 949 - 977

Published: April 8, 2024

P-Chiral phosphorus ligands received little attention in organic chemistry until Knowles made his landmark contribution asymmetric hydrogenation by developing the P-chiral CAMP and DIPAMP. The development of accelerated end last century with advent some highly efficient renowned for hydrogenation, including BisP*, TangPhos, QuinoxP*, DuanPhos, et al. However, most reported were air-sensitive, difficult to make, or lacked structural modularity, hampering their availability applicability. sterically electronically tunable is particularly desirable. Over past decade, a family hindered, electron-rich, structurally tunable, air-stable dihydrobenzooxaphosphole emerged that proved be versatile various transformations. 5 years witnessed an increasing number studies related these discovery unprecedented catalytic properties This review highlights unique catalysis applications synthesis natural products therapeutic agents.

Language: Английский

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Enantioselective Construction of Eight‐Membered N‐Heterocycles from Simple 1,3‐Dienes via Pd(0) Lewis Base Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(6)

Published: Dec. 15, 2023

Abstract We report herein an unprecedented enantioselective (4+4) cycloaddition of simple 1,3‐dienes with azadienes for the construction fused eight‐membered N ‐heterocycles. In this transformation, π‐Lewis basic Pd(0) catalyst achieves activation to induce nucleophilic addition followed by ring cyclization via a selective terminal allylic substitution. Furthermore, highly efficient and diastereoselective derivatizations rings provide facile access diverse enantiopure tetra‐ hexacyclic compounds potential application in medicinal chemistry.

Language: Английский

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Facile Synthesis of Quinoline-Substituted 3-Hydroxy-2-oxindoles and 3-Amino-2-oxindoles via a Palladium-Catalyzed Cascade Intramolecular Cyclization/Intermolecular Nucleophilic Addition Reaction

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(5), P. 3413 - 3418

Published: Feb. 20, 2024

An efficient cascade intramolecular cyclization/intermolecular nucleophilic addition reaction of allenyl benzoxazinone with isatin or isatin-derived ketimine has been established by using Pd0-π-Lewis base catalysis. A series 3-hydroxy-2-oxindoles and 3-amino-2-oxindoles quaternary carbon atoms at the C3 position were synthesized in good yields under mild conditions through this protocol.

Language: Английский

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Palladium(0) and Brønsted Acid Co‐catalyzed Enantioselective Hydro‐Cyclization of 2,4‐Dienyl Hydrazones and Oximes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(44)

Published: Aug. 6, 2024

Abstract The transition metal‐catalyzed asymmetric hydro‐functionalization of 1,3‐dienes has been well explored, but most reactions focus on electron‐neutral substrates in an intermolecular manner. Here we first demonstrate that readily available 2,4‐dienyl hydrazones and oximes can be efficiently utilized the hydro‐cyclization reaction under co‐catalysis a Brønsted acid chiral palladium complex, furnishing multifunctional dihydropyrazones dihydroisoxazoles, respectively. Diverse substitution patterns for both types electron‐deficient diene compounds are tolerated, corresponding heterocycles were generally constructed with moderate to excellent enantioselectivity, which elaborated access products higher molecular complexity diversity. Control experiments density functional theory calculations support α‐regioselective protonation dienyl by concurrent π‐Lewis base activation Pd 0 complex is energetically favoured formation active π‐allylpalladium intermediates, outer‐sphere allylic amination or etherification mode adopted deliver observed cyclized enantioselectively.

Language: Английский

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