Recent Advances in Cyclization Reactions of 1,6‐Enynes

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(6), P. 1220 - 1268

Published: Jan. 22, 2024

Abstract Elaborated molecular architectures, specifically those bearing one or more carbon stereocenters, stand as an important class of carbocyclic and heterocyclic frameworks because they are frequently occurring core structures in numerous natural products biologically active pharmaceutical molecules. Over the past few decades, development versatile synthetic approaches via cascade cyclization reactions 1,6‐enynes for construction a series fused spiro compounds has been focus great deal research initiatives. These synthesis strategies peculiarly fascinating context assembly wide array molecules, products, agrochemicals, functional materials. In this review, recent developments transformations with diverse coupling reagents summarized since 2018, which could be divided into five categories: 1) Introduction; 2) Transition metal catalyzed 1,6‐enynes; 3) Metal‐free 4) Visible‐light‐induced 5) Electrocatalytic 1,6‐enynes.

Language: Английский

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Nickel-catalyzed switchable arylative/endo-cyclization of 1,6-enynes

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 4, 2024

Abstract Carbo- and heterocycles are frequently used as crucial scaffolds in natural products, fine chemicals, biologically pharmaceutically active compounds. Transition-metal-catalyzed cyclization of 1,6-enynes has emerged a powerful strategy for constructing functionalized carbo- heterocycles. Despite significant progress, the regioselectivity alkyne functionalization is entirely substrate-dependent. And only exo -cyclization/cross-coupling products can be obtained, while endo -selective cyclization/cross-coupling remains elusive still poses formidable challenge. In this study, we disclose nickel-catalyzed switchable arylation/cyclization which nature ligand dictates arylation, electrophilic trapping reagents determine selectivity mode. Specifically, using commercially available 1,10-phenanthroline facilitates trans -arylation/cyclization to obtain seven-membered ring 2-naphthyl-substituted bisbox promotes cis access six-membered products. Diastereoselective cyclizations have also been developed synthesis enantioenriched piperidines azepanes, core structural elements pharmaceuticals possessing important biological activities. Furthermore, experimental density functional theory studies reveal that arylation process controlled by steric hindrance ligand; reaction mechanism involves -cyclization followed Dowd-Beckwith-type expansion form

Language: Английский

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Rhodium‐Catalyzed Dual C−H Activation for Regioselective Triple Annulation of Enaminones: Access to Polycyclic Naphthopyran Derivatives

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(11), P. 1770 - 1776

Published: March 21, 2023

Abstract Rh‐catalyzed C−H activation of arenes for oxidative annulations with alkynes stands out as a protocol polycyclic scaffolds. This perspective drives us to disclose herein rhodium catalyzed regioselective triple annulation enaminones hydroxyl‐alkynoates via double functionalization naphtho‐pyran Secondary coordination OH in alkynoate dictated the regioselectivity. Initial lactonization occurred chemoselectively on enamine part carbo rhodation followed by reductive elimination. was scalable and has shown high functionality tolerance. KIE studies were done get insight mechanism, some downstream transformations achieved show synthetic potential method.

Language: Английский

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Photoinduced arylative formal 4-endo-dig cyclization of propargyl alcohols/amines to access strained heterocycles

Green Chemistry, Journal Year: 2024, Volume and Issue: 26(5), P. 2705 - 2711

Published: Jan. 1, 2024

A novel synthetic strategy to access strained heterocycles is revealed through photocatalysed annulative formal 4- endo-dig cyclization of propargyl alcohols/amines with benzoquinones under catalyst/reagent-free conditions using non-hazardous solvent.

Language: Английский

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Rhodium-Catalyzed Coordination-Assisted Regioselective and Migratory Three-Point Double Annulation of o-Alkenyl Phenols with Tertiary Propargyl Alcohols

Organic Letters, Journal Year: 2022, Volume and Issue: 24(28), P. 5062 - 5067

Published: July 11, 2022

We disclose herein a Rh(III)-catalyzed migratory three-point double annulation of o-alkenyl phenols with propargyl alcohols for de novo construction naphtho furan derivatives in regio- and chemoselective manner. The protocol orchestrates two new rings four bonds one operation without the need any additive. Necessary labeled control experiments are conducted to elucidate reaction mechanism. A tertiary hydroxyl group is found be crucial both controlling regioselective insertion alkyne through chelation rhodium form key spiro cyclic intermediate forcing ring expansion via unusual selective olefin reshuffling, apart from forming an extra (furan) ring. scalable shows tolerance late stage functionalization natural products.

Language: Английский

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Pd-Catalyzed Selective Arylative Cascade Cyclization of 1,6-Diynes and Dibenzoxaborins for Fused Naphthalene Derivatives

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: April 10, 2025

A palladium-catalyzed new mode of cascade arylative cyclization 1,6-diynes is disclosed using dibenzoxaborin as an arylating agent featuring transmetalation and selective migratory insertion the key steps. This process enables efficient construction polysubstituted fused naphthalene skeletons via formation three C-C bonds through dual regioselectivity in both arylation well C-H functionalization. Some control experiments kinetic isotope effect (KIE) studies were conducted to elucidate reaction mechanism, some product diversifications achieved showcase synthetic potential.

Language: Английский

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Highly efficient and fast synthesis of di-iodinated succinimide derivatives from 1,6-enyne and I₂ under air at room temperature

Green Chemistry, Journal Year: 2022, Volume and Issue: 24(20), P. 8021 - 8028

Published: Jan. 1, 2022

A metal-free, additive-free, and practical method for the synthesis of diiodinated succinimide derivatives has been achieved under mild conditions.

Language: Английский

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Recent developments in nickel-catalyzed asymmetric cyclization and cycloaddition of carbonyl-alkynes, cyano-alkynes, and enynes

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(30), P. 4405 - 4422

Published: Jan. 1, 2023

Alkynes as unsaturated hydrocarbons have long been used for cyclization reactions. Various transition metal-catalyzed cyclizations of alkynes reported in the past decades. In this minireview, we mainly summarize recent asymmetric with other functional groups such carbonyl-alkynes, cyano-alkynes, and enynes under catalytic system nickel chiral ligands.

Language: Английский

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Recent advances in sulfur/sulfonyl radical triggered cascade cyclization reactions of 1,n-enynes

Tetrahedron, Journal Year: 2023, Volume and Issue: 138, P. 133409 - 133409

Published: April 7, 2023

Language: Английский

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Cobalt(III)-Catalyzed Free-Amine-Directed Site-Selective Allylation in 2-Aminobiaryls with Vinyl Cyclopropanes

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(19), P. 12543 - 12552

Published: Sept. 11, 2023

2-Aminobiaryls are privileged scaffolds, and their cogent synthesis diversifications, particularly through the C–H bond activation strategy, a continuous enterprise in organic synthesis. In this realm, capitalizing on susceptible native amine (−NH2) directing group is beneficial but increasingly challenging owing to its innate nucleophilic reactivity. Additionally, reactions of class substrates have traditionally been restricted cross-ring bond, as ortho-C–H functionalization presumably requires formation strained high-energy four-membered metallacycle. Herein, we report free-amine-directed reaction 2-aminobiaryls under high-valent Cp*Co(III)-catalysis, enabling regio- stereoselective allylation high yields. The protocol engages vinyl cyclopropanes allyl synthons, where C–C construction event tunneled process forge an internal olefin with exclusive (E)-selectivity. products were judicially used access high-value benzo[d]isoxazoles dihydrophenanthridine derivatives. Mechanistic experiments DFT calculations also conducted unravel rationale behind unique site selectivity, thermodynamic constraints corresponding intermediates favor over functionalization.

Language: Английский

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