Asymmetric Synthesis of a Fused Tricyclic Hydronaphthofuran Scaffold by Desymmetric [2+2+2] Cycloaddition

Teng, Quincy; Mao, Wenxiu; Chen, Dong; Wang, Zhen; Tung, Chen‐Ho; Xu, Zhenghu

doi:10.1002/anie.201911071

Cited by 46 publications

(20 citation statements)

References 72 publications

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“…From the above observations and earlier knowledge from the relevant literature, [5,7c,8a–c] we proposed a plausible mechanism as shown in Scheme 7. An active cationic metal complex must have formed with the ligand which initially annulated with enyne to give rhodacyclopentene A .…”

Section: Figurementioning

confidence: 65%

“…Another similar annulation with brominated active methylenes was reported by the same group, through Cu‐catalysis (Scheme 1b) [6c] . Further, there are some commendable reports on annulations of enynyl ethers with acetylenes/alkynes [7a] towards bi‐ and tri‐cyclic motifs with one or two new 3°‐chiral junctions (Scheme 1c and d) [7b,c] . Exploring for novel annulations in this arena, we [9] herein describe a hydrative annulation [8] of acetylenes with enynyl ethers for cyclopenta[b] benzofuranol motifs possessing two new quarternary chiral centers.…”

Section: Figurementioning

confidence: 68%

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Diastereoselective [2+2+1] Hydrative Annulation of Phenol‐Linked 1,6‐Enynes with Acetylenes Through Rhodium Catalysis: A Rapid Access to Cyclopenta[b]benzofuranols

Nagireddy

Dattatri

Nanubolu

et al. 2021

Chemistry A European J

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An unprecedented [2+2+1] hydrative annulation of 1,6‐enynes with terminal alkynes is achieved using catalytic cationic Rh(I). Thus, a modular assembly of cyclopenta[b]benzofuranols with two consecutive quarternary stereocenters is achieved from readily available alkynes. The reaction is proposed to go through a sequence of 5‐membered rhoda‐cycle formation, regioselective acetylene insertion, 1,5 H‐shift, substrate controlled stereoselective addition of water molecule followed by 1,2‐rhodium migration gave contracted rhoda‐cycle D and reductive elimination. Necessary control/labelling experiments were conducted to gain insight in to the mechanism.

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Section: Figurementioning

confidence: 65%

Section: Figurementioning

confidence: 68%

Diastereoselective [2+2+1] Hydrative Annulation of Phenol‐Linked 1,6‐Enynes with Acetylenes Through Rhodium Catalysis: A Rapid Access to Cyclopenta[b]benzofuranols

Nagireddy

Dattatri

Nanubolu

et al. 2021

Chemistry A European J

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“…In 2020, Xu and co-workers developed an enantioselective Rh(I)-catalyzed [2+2+2] cycloaddition of cyclic 1,6enynes with terminal alkynes to provide fused tricyclic hydronaphthofuran scaffolds having three contiguous stereocenters (Scheme 36). 98 The reaction was best performed with [Rh(cod) 2 ]BF 4 /(S)-BINAP (5 mol%) as a catalyst at 40 °C in DCE for a range of terminal alkynes and enynes having aliphatic or phenyl groups on the quaternary carbon center to afford the desired hydronaphthofuran derivatives in 10-84% yield and 96->99% ee. This desymmetric [2+2+2] cycloaddition was sensitive to steric hindrance that governed both the regioselectivity and the reactivity, with the formation of the other regioisomer observed when replacing the methyl group on the quaternary carbon center of the enyne with an ethyl substituent, whereas a lower yield of 10% was obtained when a phenyl-substituted enyne was used.…”

Section: Scheme 34mentioning

confidence: 99%

Recent Progress in Metal-Catalyzed [2+2+2] Cycloaddition Reactions

Matton¹,

Huvelle²,

Haddad³

et al. 2021

Synthesis

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Metal-catalyzed [2+2+2] cycloaddition is a powerful tool that allows rapid construction of functionalized 6-membered carbo- and heterocycles in a single step through an atom-economical process with high functional group tolerance. The reaction is usually regio- and chemoselective although selectivity issues can still be challenging for intermolecular reactions involving the cross-[2+2+2] cycloaddition of two or three different alkynes and various strategies have been developed to attain high selectivities. Furthermore, enantioselective [2+2+2] cycloaddition is an efficient means to create central, axial, and planar chirality and a variety of chiral organometallic complexes can be used for asymmetric transition-metal-catalyzed inter- and intramolecular reactions. This review summarizes the recent advances in the field of [2+2+2] cycloaddition.1 Introduction2 Formation of Carbocycles2.1 Intermolecular Reactions2.1.1 Cyclotrimerization of Alkynes2.1.2 [2+2+2] Cycloaddition of Two Different Alkynes2.1.3 [2+2+2] Cycloaddition of Alkynes/Alkenes with Alkenes/Enamides2.2 Partially Intramolecular [2+2+2] Cycloaddition Reactions2.2.1 Rhodium-Catalyzed [2+2+2] Cycloaddition2.2.2 Molybdenum-Catalyzed [2+2+2] Cycloaddition2.2.3 Cobalt-Catalyzed [2+2+2] Cycloaddition2.2.4 Ruthenium-Catalyzed [2+2+2] Cycloaddition2.2.5 Other Metal-Catalyzed [2+2+2] Cycloaddition2.3 Totally Intramolecular [2+2+2] Cycloaddition Reactions3 Formation of Heterocycles3.1 Cycloaddition of Alkynes with Nitriles3.2 Cycloaddition of 1,6-Diynes with Cyanamides3.3 Cycloaddition of 1,6-Diynes with Selenocyanates3.4 Cycloaddition of Imines with Allenes or Alkenes3.5 Cycloaddition of (Thio)Cyanates and Isocyanates3.6 Cycloaddition of 1,3,5-Triazines with Allenes3.7 Cycloaddition of Aldehydes with Enynes or Allenes/Alkenes3.8 Totally Intramolecular [2+2+2] Cycloaddition Reactions4 Conclusion

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“…Later, Xu [28] et al reported the rapid Rh(I)-catalyzed oxidative region-and stereoselective desymmetric [2 + 2 + 2] cycloaddition of alkyne-tethered cyclohexadienone 24.1 for the construction of fused tricyclic scaffolds 24.3 or 24.4 having three contiguous stereocenters in a single step (Scheme 24). The formation of the desired tricyclic product was found to be diminished in the protic solvent MeOH/DCE mixture and majorly produced bicyclic hydrobenzofuran products 23.2 as explained in Scheme 23.…”

Section: Rhodium-catalyzed Reactionsmentioning

confidence: 99%

Transition‐Metal Catalyzed Stereoselective Desymmetrization of Prochiral Cyclohexadienones

Munakala

Phanindrudu

Chegondi

2021

The Chemical Record

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The development of transition-metal catalyzed enantioselective and diastereoselective transformations has contributed many advances in the field of synthetic organic chemistry. Particularly, stereoselective desymmetrization of prochiral cyclohexadienones represents a powerful strategy for accessing highly functionalized and stereochemically enriched scaffolds, which are often found in biologically active compounds and natural products. In recent years, several research groups including our group have made a significant progress on transition-metal catalyzed stereoselective desymmetrizations of 2,5-cyclohexadienones. In this account, we will provide an overview of the recent developments in this area employing Pd, Cu, Rh, Au, Ag, Ni, Co, and Mn-catalysts.

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Asymmetric Synthesis of a Fused Tricyclic Hydronaphthofuran Scaffold by Desymmetric [2+2+2] Cycloaddition

Cited by 46 publications

References 72 publications

Diastereoselective [2+2+1] Hydrative Annulation of Phenol‐Linked 1,6‐Enynes with Acetylenes Through Rhodium Catalysis: A Rapid Access to Cyclopenta[b]benzofuranols

Diastereoselective [2+2+1] Hydrative Annulation of Phenol‐Linked 1,6‐Enynes with Acetylenes Through Rhodium Catalysis: A Rapid Access to Cyclopenta[b]benzofuranols

Recent Progress in Metal-Catalyzed [2+2+2] Cycloaddition Reactions

Transition‐Metal Catalyzed Stereoselective Desymmetrization of Prochiral Cyclohexadienones

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