Recent Advances in the Gold-Catalyzed Reactions of Propargyl Esters

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(12), P. 1406 - 1420

Published: June 6, 2023

ConspectusLate-transition-metal-based complexes represent an indispensable catalytic tool in chemical synthesis due to their ability increase molecular complexity rapidly and efficiently from readily accessible substrates a single operation. Added this is the exquisite control of product chemo-, diastereo-, enantio-, site-selectivities achieved by systems transition-metal salts that have been developed mediate wide range functional group transformations. Within venerable synthetic toolbox, Au(I) Au(III) emerged recent years as invaluable addition result potent σ- π-Lewis acidities stabilize cationic reaction intermediates. The insights provided mechanistic studies examining various electronic, steric, stereoelectronic factors at play organogold species are expected be formed chemistry complex also pivotal understanding exploring potential utility. Illustrative this, for example, contribution made gold-catalyzed cycloisomerization propargyl esters strategies variety bioactive natural products compounds current pharmaceutical materials interest. This Account summarizes our efforts over past decade toward realizing new single-step carbocyclic heterocyclic relied on reactions esters. It outlines methods exploited unique reactivities gold-carbene typically generated [2,3]-sigmatropic rearrangement compound class containing terminal or electron-deficient alkyne moiety exposure salt. describes realization initiated 1,3-acyloxy migration with electronically unbiased disubstituted C≡C bond delivers corresponding allenyl ester primed further reactivity activation 11 metal complex. part ongoing overarching program within was focused determining gold catalysis would enable application recognizable disconnections retrosynthetic analysis. They were additionally aimed evaluating opportunities offered relativistic effects possessed complex, most pronounced among d-block elements thus catalyst choice chemistry, generate space. For instance, we demonstrated several 1,3- 1,4-enyne reliable strategy situ formation 1,4-cyclopentadienyl derivatives. Their appropriately placed second starting material then shown afford targets five-membered ring structure. An example assembly member 1H-isoindole family found exhibit TNF-α (tumor necrosis factor-α) inhibitor activity.

Language: Английский

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Gold-Catalyzed Double Spirocyclization of 3-Ene-1,7-diyne Esters to Dispiroheterocycles

Organic Letters, Journal Year: 2024, Volume and Issue: 26(15), P. 3252 - 3257

Published: April 8, 2024

A synthetic method to prepare dispiroheterocycles containing two all-carbon quaternary centers efficiently that relies on the gold(I)-catalyzed double spirocyclization of 3-ene-1,7-diyne esters is described. The suggested mechanism delineates a rare example dispirocyclization featuring 1,n-acyloxy shifts comprising 1,3-acyloxy migration and an interrupted 1,5-acyl was achieved with assistance residual water in reaction media.

Language: Английский

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Enantioselective and Regiodivergent Synthesis of Dihydro-1,2-oxazines from Triene-Carbamates via Chiral Phosphoric Acid-Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(48), P. 26504 - 26515

Published: Nov. 27, 2023

Conjugated trienes are fascinating building blocks for the rapid construction of complex polycyclic compounds. However, limited success has been achieved due to challenging regioselectivity control. Herein, we report an enantio- and diastereoselective process allowing regioselectively control functionalization NH-triene-carbamates. Synthesis chiral cis-3,6-dihydro-2H-1,2-oxazines is by a phosphoric acid catalyzed Nitroso-Diels-Alder cycloaddition involving [(1E,3E,5E)-hexa-1,3,5-trien-1-yl]carbamates. Moreover, modular access three different regioisomers with excellent diastereoselectivities high enantioselectivities obtained careful choice reaction conditions. A computational study reveals that influenced steric demand substituents at 6-position triene, as well noncovalent interactions between two partners. Utility each regioisomeric cycloadduct highlighted variety synthetic transformations.

Language: Английский

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Gold-Catalyzed Cascade Cycloisomerization of 3-Allyloxy-1,6-diynes to Cyclopropyl- and Cyclobutyl-Fused Benzofurans and Chromen-3a(1H)-ols

Organic Letters, Journal Year: 2024, Volume and Issue: 26(13), P. 2635 - 2640

Published: March 25, 2024

A synthetic method for the efficient preparation of partially hydrogenated benzo[f]cyclobuta[cd]cyclopenta[h]benzofurans and cyclopropa[c]chromen-3a(1H)-ols that relies on gold(I)-catalyzed cascade cycloisomerization 3-allyloxy-1,6-diynes is described.

Language: Английский

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Denitrative Formal [5 + 1] Cycloaddition of 1‐(2‐Nitrophenyl)‐2‐yn‐1‐ones with Thioacetamide under Transition Metal‐Free Conditions. Synthesis of Thiochromen‐4‐ones

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: May 31, 2024

Abstract A new strategy for thiochromen‐4‐one synthesis that relies on the denitrative formal [5+1] cycloaddition of 1‐(2‐nitrophenyl)‐2‐yn‐1‐ones with thioacetamide is described. Achieved under reaction conditions did not require transition metal catalysis, nor exclusion air or moisture, suggested to involve exploiting propensity undergo hydrolysis basic conditions. This follows by addition ensuing sulfide anion 1,3‐alkynone and a nucleophilic aromatic substitution rearomatization cascade give S ‐heterocyclic product in yields 41–99 %.

Language: Английский

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Ligand-controlled chemoselectivity in gold-catalyzed cascade cyclization of 1,4-diene-tethered 2-alkynylbenzaldehydes

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(23), P. 6520 - 6529

Published: Jan. 1, 2022

A synthetic method that relies on the gold( i )-catalyzed cascade annulation of skipped 1,4-diene-tethered 2-alkynylbenzaldehydes for chemo- and stereoselective assembly polycyclic bridged-pyrrolidines -azepines is described.

Language: Английский

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Dodging the Conventional Reactivity of o-Alkynylanilines under Gold Catalysis for Distal 7-endo-dig Cyclization

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(4), P. 2260 - 2287

Published: Feb. 6, 2023

A direct ring-closing strategy involving a less facile 7-endo-dig carbacyclization of o-alkynylaniline derivatives for the synthesis benzo[b]azepines has been presented. The trivial well-documented 5-endo-dig cyclization in due to high nucleophilicity nitrogen overcome by using their vinylogous amides under gold catalysis access wide array an atom economical way with excellent functional group compatibility. Deuterium scrambling experiments and DFT studies favor mechanism stabilizing conformational change initially formed seven-membered vinyl intermediate through key cyclopropyl carbene its subsequent protodeauration mediated counter anion.

Language: Английский

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Gold catalyzed spirocyclization of 1-ene-4,9- and 3-ene-1,7-diyne esters to azaspiro[4.4]nonenones and azaspiro[4.5]decadienones

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 11(3), P. 761 - 768

Published: Nov. 27, 2023

A method to prepare a structurally diverse range of spirocyclic cyclopentanes, furans, pyrrolidines and piperidines, which relies on the gold( i )-catalyzed spirocyclization 1-ene-4,9- 3-ene-1,7-diyne esters, has been developed.

Language: Английский

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Chiral Brønsted Acid-Catalyzed Regio-, Diastereo-, and Enantioselective Formal [2 + 2 + 2] Cycloaddition of 3-Vinyl-1H-indoles with Nitrosobenzenes

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(17), P. 13269 - 13282

Published: Aug. 21, 2024

A chiral Brønsted acid-catalyzed synthetic method that enables the enantioselective formal [2 + 2 2] cycloaddition of 3-vinyl-1H-indoles with nitrosobenzenes is described. Through this previously unknown mode reactivity nitrosoarene, ring formation protocol offers access to a wide variety fully substituted 1,2-oxazinanes as single regioisomer. With four stereogenic centers generated in product, N,O-heterocycle was also furnished, most cases, diastereomer yields up 94% and enantiomeric excess (ee) values 99%. The utility catalytic demonstrated by mmol scale preparation one example its further functional group transformations. Included selective conversion 1,2-oxazinane either tetrahydrofuran or partially hydrogenated pyrrole derivative. Experimental computational studies based on azaphilic hydrogen-bonding interactions between two substrates phosphoric acid provide insight into observed product selectivities.

Language: Английский

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Recent Advances in the Synthetic Applications of Nitrosoarene Chemistry

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 20, 2024

This review covers reactions involving nitrosoarenes over the last decade, including cyclization, with attacks at oxygen or nitrogen terminus, dimerization, rearrangement, coordination, and other significant reactions.

Language: Английский

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