<i>ipso</i>‐Arylative Ring‐Opening Polymerization as a Route to Electron‐Deficient Conjugated Polymers

Shih, Feng-Yang; Choi, Deokkyu; Wu, Qin; Nam, Chang‐Yong; Grubbs, Robert B.

doi:10.1002/anie.201809610

Cited by 5 publications

(7 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus the aryl ring that tends to break the C–C bond will approach the Pd atom to construct axial chirality. Third, the reaction prefers to break the C–C bond attached to the thiophene ring, which has been confirmed in previous studies. ,, …”

supporting

confidence: 78%

“…In 2019, Grubbs et al realized a Pd-catalyzed regioselective ringopening/C−C cleavage polymerization for the synthesis of polythiophene (P1, P2)-bearing conjugated aroylphenyl side chains, which are excellent candidates for n-type organic semiconductors (Scheme 1a). 4,5 Axially chiral biaryl compounds are widespread in natural products and pharmaceuticals. 6 Furthermore, they are one class of the most effective scaffolds for chiral ligands and catalysts.…”

mentioning

confidence: 99%

“…Third, the reaction prefers to break the C−C bond attached to the thiophene ring, which has been confirmed in previous studies. 4,5,15 We started our investigation with (±)-1a and 1-bromo-4methoxybenzene (2a) as the model substrates (Scheme 3). In the presence of NaH, the reaction catalyzed by Pd-(CH 3 CN) 2 Cl 2 and phosphoramidite (L1) in toluene gave 61% ee of (S)-1a and 81% ee of (R a )-3a (corresponding to a conversion of 43%).…”

mentioning

confidence: 99%

“…Thiophene-based structures, including oligomers and polymers, have wide applications in organic light-emitting diiodes (OLEDs) and organic photovoltaics (OPVs). − Thiophenes are frequently used as powerful building blocks to tune the optical and electronic properties of different materials by changing the HOMO–LUMO gap. In 2019, Grubbs et al realized a Pd-catalyzed regioselective ring-opening/C–C cleavage polymerization for the synthesis of polythiophene ( P1 , P2 )-bearing conjugated aroylphenyl side chains, which are excellent candidates for n-type organic semiconductors (Scheme a). , …”

mentioning

confidence: 99%

See 3 more Smart Citations

Atroposelective Kinetic Resolution of 8H-Indeno[1,2-c]thiophen-8-ols via Pd-Catalyzed C–C Bond Cleavage Reaction

Yang

et al. 2022

Org. Lett.

View full text Add to dashboard Cite

The present work demonstrates a palladium-catalyzed kinetic resolution/ring-opening reaction of 8H-indeno[1,2c]thiophen-8-ols. The reaction proceeds in a highly regioselective manner, and both optically active thiophene-phenyl atropisomers and stereogenic 8H-indeno[1,2-c]thiophen-8-ols were obtained with high enantiomeric excesses. The synthetic applications of the obtained thiophenyl atropisomers were briefly investigated.

show abstract

supporting

confidence: 78%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Atroposelective Kinetic Resolution of 8H-Indeno[1,2-c]thiophen-8-ols via Pd-Catalyzed C–C Bond Cleavage Reaction

Yang

et al. 2022

Org. Lett.

View full text Add to dashboard Cite

show abstract

“…As displayed in TS1 and TS2 , axial chirality will be built during the process of the aryl ring approaching the Pd atom. Since the carbon–carbon bond connected to the thiophene ring is more favored to be cleaved than the one connected to the phenyl ring, − the process through intermediate Int16 is significantly faster than that through intermediate Int15 . Thus, the kinetic resolution of (±)- 30a can be realized.…”

Section: Asymmetric Ring-opening Through C–c Bond Cleavagementioning

confidence: 99%

Transition Metal-Catalyzed Biaryl Atropisomer Synthesis via a Torsional Strain Promoted Ring-Opening Reaction

Zhang

Zhao

2022

Acc. Chem. Res.

View full text Add to dashboard Cite

Conspectus Arising from the restricted rotation of a single bond caused by steric or electronic effects, atropisomerism is one of the few fundamental categories for molecules to manifest their three-dimensional characters into which axially chiral biaryl compounds fall. Despite the widespread occurrence of axially chiral skeletons in natural products, bioactive molecules, and chiral ligands/organocatalysts, catalytic asymmetric methods for the synthesis of these structures still lag behind demand. Major challenges for the preparation of these chiral biaryls include accessing highly sterically hindered variants while controlling the stereoselectivity. A couple of useful strategies have emerged for the direct asymmetric synthesis of these molecules in the last two decades. Recently, we have engaged in catalytic asymmetric synthesis of biaryl atropisomers via transition metal catalysis, including asymmetric ring-openings of dibenzo cyclic compounds. During these studies, we serendipitously discovered that the two substituents adjacent to the axis cause these dibenzo cyclic molecules to be distorted to minimize steric repulsion. The distorted compounds display higher reactivity in the ring-opening reactions than the non-distorted molecules. In other words, torsional strain can promote a ring-opening reaction. On the basis of this concept, we have successfully realized the catalytic asymmetric ring-opening reaction of cyclic diaryliodoniums, dibenzo silanes, and 9H-fluoren-9-ols, which delivered several differently substituted ortho tetra-substituted biaryl atropisomers in high enantioselectivity. The torsional strain not only activates the substrates toward ring-opening under mild conditions but also changes the chemoselectivity of bond-breaking events. In the palladium-catalyzed carboxylation of S-aryl dibenzothiophenium, the torsional strain inversed the bond selectivity from exocyclic C–S bond cleavage to the ring-opening reaction. In this Account, we summarize our studies on copper-, rhodium-, or palladium-catalyzed asymmetric ring-opening reactions of dibenzo cyclic compounds as a useful collection of methods for the straightforward preparation of ortho tetra-substituted biaryl atropisomers with high enantiopurity on the basis of the above-mentioned torsional strain-promoted ring-opening coupling strategy. In the last part, the torsional strain energies are also discussed with the aid of density functional theory (DFT) calculations.

show abstract

From Peripheral Stereogenic Center to Axial Chirality: Synthesis of 3‐Arylthiophene Atropisomers

Hong

et al. 2022

Adv Synth Catal

View full text Add to dashboard Cite

A practical synthesis of axially chiral biaryls via chirality transfer from peripheral stereogenic carbon centers is reported. In contrast to the traditional aromatization process of a non-aromatic structure with ipso stereogenic centers, this method is based on a Pd-catalyzed carbon-carbon bond cleavage/ring-opening reaction of optically active 8H-indenothiophen-8-ols with an achiral ligand, enabling synthesis of highly functionalized 3-arylthiophene atropisomers in high enantioselectivity.

show abstract

ipso‐Arylative Ring‐Opening Polymerization as a Route to Electron‐Deficient Conjugated Polymers

Abstract: This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record.

Cited by 5 publications

References 36 publications

Atroposelective Kinetic Resolution of 8H-Indeno[1,2-c]thiophen-8-ols via Pd-Catalyzed C–C Bond Cleavage Reaction

Atroposelective Kinetic Resolution of 8H-Indeno[1,2-c]thiophen-8-ols via Pd-Catalyzed C–C Bond Cleavage Reaction

Transition Metal-Catalyzed Biaryl Atropisomer Synthesis via a Torsional Strain Promoted Ring-Opening Reaction

From Peripheral Stereogenic Center to Axial Chirality: Synthesis of 3‐Arylthiophene Atropisomers

Contact Info

Product

Resources

About