Gold‐Catalyzed Enantioselective Annulations

Chemistry - A European Journal, Journal Year: 2016, Volume and Issue: 23(3), P. 467 - 512

Published: Oct. 10, 2016

Abstract In the past decade, there have been many extraordinary advances in development of gold‐catalyzed enantioselective annulations, such as cycloadditions, cyclizations, cycloisomerizations, and tandem which are particular interest owing to their potential for rapid construction optically active hetero‐ carbocyclic molecules. This Review summarizes methods construct chiral cyclic compounds by annulations reported since 2005. The is organized according general annulation types catalyzed gold complexes or salts, four main (cycloadditions, cyclizations C−C multiple bonds with tethered nucleophiles, cycloisomerization cyclization enynes, annulations), well some other strategies. reaction mechanisms each subcategory, key intermediates unusual transformations, application several novel ligands salts also discussed.

Language: Английский

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Allenes and Derivatives in Gold(I)- and Platinum(II)-Catalyzed Formal Cycloadditions

Accounts of Chemical Research, Journal Year: 2019, Volume and Issue: 52(2), P. 465 - 479

Published: Jan. 14, 2019

ConspectusCycloaddition reactions, by involving the formation of at least two bonds and one cycle in a single operation, represent more practical ways to assemble carbo- heterocyclic structures from simple acyclic precursors. Especially appealing are formal cycloadditions promoted transition metals, owing ability these reagents open mechanisms that not accessible using classical chemistry. Therefore, along years, great variety annulations based on first-, particularly second-row metals have been discovered. Most reactions involve inner sphere mechanisms, with metal participating via standard oxidative addition or reductive elimination processes. Curiously, third row like platinum and, especially, gold remained largely unexplored, likely because belief they were inert expensive. However, beginning this century, many groups realized can very interesting mechanistic scenarios promote novel types transformations. In particular, π-acidic, carbophilic behavior gold(I) complexes, together possibility tuning their reactivity designed ligands, has triggered important activity field. Many gold-catalyzed transformations involved cycloisomerization processes, but during recent there also advances development cycloaddition reactions. While rely activation alkynes, an increasing number reports exploit peculiar reactivities allenes derivatives.In Account, we present efforts platinum- allenes. For sake simplicity, only include initiated direct metal-promoted allene moiety. Thus, alternative Pt- Au-catalyzed wherein does interact catalyst covered. Upon generate allyl-cation alkenylmetal species behave as 1,2- 1,3-carbon dipoles relevant is allenamides. The presence amide substituent provides for generation intermediates good balance stability, which therefore react corresponding partners controlled manner. Moreover, despite difficulties associated transfer stereochemical information chiral linear enantioselective discovered.This Account organized considering atoms engaged annulation process, when possible, results chronological order.

Language: Английский

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Gold-Catalyzed Synthesis of Small Rings

Chemical Reviews, Journal Year: 2020, Volume and Issue: 121(14), P. 8613 - 8684

Published: Nov. 2, 2020

Three- and four-membered rings, widespread motifs in nature medicinal chemistry, have fascinated chemists ever since their discovery. However, due to energetic considerations, small rings are often difficult assemble. In this regard, homogeneous gold catalysis has emerged as a powerful tool construct these highly strained carbocycles. This review aims provide comprehensive summary of all the major advances discoveries made gold-catalyzed synthesis cyclopropanes, cyclopropenes, cyclobutanes, cyclobutenes, corresponding heterocyclic or heterosubstituted analogs.

Language: Английский

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Enantioselective Dicarbofunctionalization of Unactivated Alkenes by Palladium‐Catalyzed Tandem Heck/Suzuki Coupling Reaction

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(41), P. 14653 - 14659

Published: Aug. 17, 2019

Abstract A highly enantioselective dicarbofunctionalization of unactivated alkenes was implemented by a Pd‐catalyzed asymmetric tandem Heck/Suzuki coupling reaction. This reaction represents the first example intramolecular cyclization/cross‐coupling olefin‐tethered aryl halides with alkyl‐, alkenyl‐ or arylboronic acids, and provides rapid access to number chiral compounds, such as dihydrobenzofurans, indolines, chromanes, indanes bearing quaternary stereocenter, in good yields excellent enantioselectivities. The practicality this validated modification biologically complex molecules peptides, piperitol, CB2 receptor agonists, etc. Moreover, synthesis two enantiomers can be easily realized simple change order steps sequence.

Language: Английский

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P-Chiral Phosphines Enabled by Palladium/Xiao-Phos-Catalyzed Asymmetric P–C Cross-Coupling of Secondary Phosphine Oxides and Aryl Bromides

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(51), P. 20556 - 20564

Published: Dec. 2, 2019

The development of transition-metal-catalyzed methods for the synthesis P-chiral phosphine derivatives poses a considerable challenge. Herein, we present direct Pd/Xiao-Phos-catalyzed cross-coupling reaction easily accessible secondary oxides and aryl bromides, which provides rapid access to oxides. proceeds efficiently with wide array partners deliver various tertiary in up 96% yield 97% ee. Moreover, DiPAMP ligand its analogues was also realized, demonstrates suitable pathway switching branched chain DiPAMP.

Language: Английский

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Palladium‐Catalyzed Enantioselective Reductive Heck Reactions: Convenient Access to 3,3‐Disubstituted 2,3‐Dihydrobenzofuran

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(32), P. 10373 - 10377

Published: June 20, 2018

The first example of highly enantioselective intramolecular hydroarylation allyl aryl ethers was realized by palladium-catalyzed reductive heck reactions utilizing a new chiral sulfinamide phosphine ligand (N-Me-XuPhos). N-Me-XuPhos can be easily prepared on gram scale from readily available starting materials in one-pot synthesis approach. A series optically active 2,3-dihydrobenzofurans bearing quaternary stereocenter were obtained good yields and with excellent enantioselectivities. practicality this reaction validated the straightforward CB2 receptor agonists. Moreover, deuterium efficiently incorporated into products.

Language: Английский

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Palladium/PC-Phos-Catalyzed Enantioselective Arylation of General Sulfenate Anions: Scope and Synthetic Applications

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(9), P. 3467 - 3473

Published: Feb. 8, 2018

Herein we reported an efficient palladium-catalyzed enantioselective arylation of both alkyl and aryl sulfenate anions to deliver various chiral sulfoxides in good yields (up 98%) with excellent enantioselectivities 99% ee) by the use our developed O,P-ligands (PC-Phos). PC-Phos are easily prepared short steps from inexpensive commercially available starting materials. The single-crystal structure PC4/PdCl2 showed that a rarely observed 11-membered ring was formed via O,P-coordination palladium(II) center. salient features this method include general substrate scope, ease scale-up, applicable late-stage modification bioactive compounds, synthesis marketed medicine Sulindac.

Language: Английский

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Gold‐Catalyzed Asymmetric Intramolecular Cyclization of N‐Allenamides for the Synthesis of Chiral Tetrahydrocarbolines

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(50), P. 15905 - 15909

Published: Oct. 28, 2017

Abstract Highly enantioselective gold‐catalyzed intramolecular cyclization of N‐allenamides was implemented by utilizing a designed chiral sulfinamide phosphine ligand (PC‐Phos). This represents the first example highly N‐allenamides. The practicality this reaction validated in total synthesis ( R )‐desbromoarborescidine A and formal C )‐deplancheine. Moreover, catalyst system PC‐Phos/AuNTf 2 proved to be specifically efficient promote desymmetrization excellent yields with satisfactory ee values.

Language: Английский

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Enantioselective Difunctionalization of Alkenes by a Palladium‐Catalyzed Heck/Sonogashira Sequence

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(7), P. 2769 - 2775

Published: Nov. 22, 2019

Abstract Sonogashira‐type cross‐couplings are one of the most significant alkynylations in organic chemistry. One first palladium‐catalyzed intramolecular Heck/Sonogashira reactions alkenes with terminal alkynes is now reported. With this method, a variety uniquely substituted chiral benzene‐fused heterocycles bearing propargyl‐substituted all‐carbon quaternary stereocenter were obtained straightforward, high‐yielding, and highly stereoselective manner under mild conditions. Salient features process include use readily available substrates, high selectivities, broad substrate scope as well versatile product functionalizations.

Language: Английский

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Pd/PC‐Phos‐Catalyzed Enantioselective Intermolecular Denitrogenative Cyclization of Benzotriazoles with Allenes and N‐Allenamides

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(33), P. 11444 - 11448

Published: June 14, 2019

Abstract Reported herein is an asymmetric Pd/PC‐Phos‐catalyzed denitrogenative cyclization of benzotriazoles with allenes and N‐allenamides, representing the first example enantioselective cyclizations benzotriazoles. A series optically active 3‐methyleneindolines were obtained in good yields high ee values. The use inexpensive readily available starting materials, regio‐ enantioselectivity, a broad substrate scope, mild reaction conditions, no need for base, as well versatile functionalization make this approach attractive.

Language: Английский

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