Chiral Palladacycle Catalysts Generated on a Single‐Handed Helical Polymer Skeleton for Asymmetric Arylative Ring Opening of 1,4‐Epoxy‐1,4‐dihydronaphthalene

Yamamoto, Takeshi; Akai, Yuto; Suginome, Michinori

doi:10.1002/ange.201407358

Cited by 19 publications

(2 citation statements)

References 82 publications

(8 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The transition-metal-catalyzed ring opening reactions of heterobicyclic alkenes have received intense attention in the past decade as they represent versatile approaches for chiral hydronaphthalenes, which are frequently found in a plethora of natural products and biologically active molecules . The group of Lautens has taken the lead in exploring rhodium-catalyzed asymmetric ring opening reactions (ARO) of heterobicyclic alkenes; and some other groups have also achieved a lot of success by using iridium, nickel, palladium, copper, and ruthenium catalysts . Our group has long had an interest in this kind of reaction and has studied it with co-catalytic systems comprising chiral transition-metal complexes and Lewis acids as previously employed by pioneers in the field. , Followed by our previous work that employing alkynes, amines, phenols, alcohols, and organic acids as nucleophiles, the asymmetric ring-opening reaction of heterobicyclic alkenes by boronic acids has attracted our attention as they offered a straightforward method for the preparation of chiral aryltetralins, which are common substructures in bioactive natural products such as chelidonine, corynoline, and wailupemycin D .…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Ring-Opening Reactions of Aza- and Oxa-bicyclic Alkenes with Boronic Acids Using a Palladium/Zinc Co-catalytic System

et al. 2017

View full text Add to dashboard Cite

The asymmetric ring opening reactions of bicyclic alkenes with boronic acids were accomplished by using a highly active palladium/zinc co-catalytic system that was suitable for both azabenzonorbornadienes and oxabenzonorbornadienes, which were transformed to the corresponding chiral hydronaphthalene products in high yields (up to 99%) and high optical purities (up to 98% ee). The reaction protocol is general and mild and displays good functional group tolerance.

show abstract

Section: Introductionmentioning

confidence: 99%

Asymmetric Ring-Opening Reactions of Aza- and Oxa-bicyclic Alkenes with Boronic Acids Using a Palladium/Zinc Co-catalytic System

et al. 2017

View full text Add to dashboard Cite

show abstract

“…8,17 Ito and co-workers reported poly-(quinoxaline-2,3-diyl)s can act as a scaffold for chiral polymeric ligands with high enantioselectivities. 18,19 In addition, poly-(quinoxaline-2,3-diyl) films exhibited selective reflection of righthanded circular polarized light (CPL) in the visible region after annealing. 20 Fascinated by the unique structural features, we are interested in poly(5-alkyl-2,3-thiophene)s (P5AT), the ortho-linked isomers of the most studied conjugated polymers, poly(3-alkyl-2,5-thiophene)s (P3AT).…”

mentioning

confidence: 99%

Helical Poly(5-alkyl-2,3-thiophene)s: Controlled Synthesis and Structure Characterization

Zhang

Bonnesen

et al. 2016

Macromolecules

View full text Add to dashboard Cite

Whereas poly(3-alkyl-2,5-thiophene)s (P3AT), with many potential applications, have been extensively investigated, their ortho-connected isomers, poly(5-alkyl-2,3-thiophene)s (P5AT), have never been reported because of the difficulty in their syntheses. We herein present the first synthesis of regioregular P5AT via controlled Suzuki cross-coupling polymerization with PEPPSI-IPr as catalyst, affording the polymers with tunable molecular weight, narrow polydispersity (PDI), and well-defined functional end groups at the gram scale. The helical geometry of P5AT was studied by a combination of NMR, small-angle X-ray scattering (SAXS), and scanning tunneling microscopy (STM). Particularly, the single polymer chain of poly(5-butyl-2,3-thiophene) (P5BT) on highly oriented pyrolytic graphite (HOPG) substrates with either M or P helical conformation was directly observed by STM. The comparison of UV−vis absorption between poly(5-hexyl-2,3-thiophene) (P5HT) (λ = 345 nm) and poly(3-hexyl-2,5-thiophene) (P3HT) (λ = 450 nm) indicated that the degree of conjugation of the backbone in P5HT is less than in P3HT, which may be a consequence of the helical geometry of the former compared to the more planar geometry of the latter. Moreover, we found that P5HT can emit green fluorescence under UV (λ = 360 nm) irradiation. ■ INTRODUCTIONConjugated polyarylenes have found a wide range of applications including optical sensors, electrochromic devices, field effect transistors, and organic solar cells. 1−3 Their physical properties are controlled by the manner in which their rings are connected. As a result, ortho-, meta-, and para-linked polyarylenes each show distinctive optoelectronic properties and accordingly constitute different classes of functional polymers. 4,5 Although meta-and para-linked polyarylenes have been extensively investigated over the past decades, the study of poly(o-arylene)s is still at an early stage because of the synthesis challenges.It has been reported recently that oligo(o-arylene)s intrinsically possess a compressed helical structure with a helical pitch of 0.3−0.5 nm in the solid state as revealed by single crystal X-ray analysis, including oligo(o-phenylene)s, oligo(o-thiophene)s, oligo(o-thiazole)s, and oligo(o-furan)s. 6−10 Moreover, Hartley and co-workers disclosed that this compressed helical structure of oligo(o-arylene)s is stabilized by aromatic stacking interactions, 11,12 which is different from traditional helical polymers commonly stabilized by steric effects or hydrogen bonding. 13−15 Thus, due to their helical structures, oligo(o-arylene)s are reported to possess certain unique properties with potential applications different from their meta-or para-counterparts. 16 For example, Fukushima and Aida et al. reported that oligo(ophenylene)s possessed a main chain redox active property that responded to electrical inputs by a conformation change and acted as surface modifiers for homeotropic columnar ordering of discotic liquid crystals. 8,17 Ito and co-workers reported poly-(quinoxaline-2,3-diyl)s...

show abstract

Proline‐derived Long‐aliphatic‐chain Amphiphilic Organocatalysts (PDLACAOs) for Asymmetric Reactions in Aqueous Media

et al. 2020

View full text Add to dashboard Cite

Herein, a specialized review of the origin and state of the art of proline-derived long-aliphatic-chain amphiphilic organocatalysts (PDLACAOs) and their use in asymmetric organic reactions in aqueous media (water, brine, and sea water), including in water and in the presence of water, is presented. The reactions in which they have been evaluated and the most important mechanisms are discussed. Scheme 24. Michael addition reaction of dicyanoolefins 57 to α,β-unsaturated aldehydes 48 in-brine using catalyst 46 g, by Loh. Scheme 25. Michael addition reaction in brine using catalysts 59 a-c, by Ni and Headley. Scheme 26. Cross-aldol reaction using catalyst 59 c in the presence of ionic liquid system 64 in brine, by Ni and Headley.

show abstract

Chiral Palladacycle Catalysts Generated on a Single‐Handed Helical Polymer Skeleton for Asymmetric Arylative Ring Opening of 1,4‐Epoxy‐1,4‐dihydronaphthalene

Cited by 19 publications

References 82 publications

Asymmetric Ring-Opening Reactions of Aza- and Oxa-bicyclic Alkenes with Boronic Acids Using a Palladium/Zinc Co-catalytic System

Asymmetric Ring-Opening Reactions of Aza- and Oxa-bicyclic Alkenes with Boronic Acids Using a Palladium/Zinc Co-catalytic System

Helical Poly(5-alkyl-2,3-thiophene)s: Controlled Synthesis and Structure Characterization

Proline‐derived Long‐aliphatic‐chain Amphiphilic Organocatalysts (PDLACAOs) for Asymmetric Reactions in Aqueous Media

Contact Info

Product

Resources

About