Synthesis of Cross-Conjugated Polyenes via Palladium-Catalyzed Oxidative C–C Bond Forming Cascade Reactions of Allenes

Naidu, Veluru Ramesh; Bäckvall, Jan‐Erling

doi:10.1021/acs.joc.0c00186

Cited by 8 publications

(3 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar to carbo(oxa)cyclization-alkynylation of enallenes with alkynes, the coupling of allenyne ( 52a ) was also investigated by Naidu and Bäckvall, using allene-tethered alkyne ( 52b ) as the coupling partner (Scheme ). Various cross-conjugated polyenes ( 52c ) were fabricated under the previously employed oxidative conditions by adding 20 mol % Na 2 CO 3 as an additive. Aerobic biomimetic oxidative conditions were also suitable for reducing the amount of oxidant required for this transformation.…”

Section: Aa Coupling In Constructing Cyclic C-skeletonsmentioning

confidence: 99%

Intermolecular Allene–Alkyne Coupling: A Significantly Useful Synthetic Transformation

Pradhan,

Park

2024

ACS Catal.

View full text Add to dashboard Cite

Because of its wide applicability in the synthesis of diverse unsaturated building blocks, allene−alkyne (AA) coupling has emerged as a powerful methodology to drive useful chemical transformations in the past two decades. Considering recent discoveries in this active research area, in this Review, we aim to support chemists in the selection of suitable methods, particularly intermolecular approaches, according to the synthesis needs. However, inherent similarities between the reactivities of π-systems create considerable obstacles while predicting selectivity in an intermolecular platform. Therefore, herein, intermolecular couplings for the chemoselective, stereoselective, and regioselective syntheses of acyclic and cyclic C-skeletons are reviewed. However, considering the lack of a well-organized review in this field, we initially provide a brief historical overview of the types of thermally induced reactions that are mostly feasible for electronically biased coupling components and are nonselective. Subsequently, emerging selective strategies are described, which include activator-controlled and neighboring functional group-assisted regio-, stereo-, and π-skeleton-divergent processes. Overall, this Review is divided into two parts. In the first part, strategies for the fabrication of acyclic C-skeletons are explained according to the reaction types. In the second part, synthetic transformations affording cyclic structures are reviewed based on the substrate class (that is, nonassisted and assisted substrates). Key reaction intermediates of each subset of coupling and factors affecting productselective discrimination of the active species with the highlight of rationale are systemically summarized. Understanding of these substrate structure-and catalyst-dependent factors provides insights into the regulation of the chemoselectivities of title AA crosscouplings and, therefore, the design of alternative catalytic routes with distinct mechanistic features.

show abstract

Section: Aa Coupling In Constructing Cyclic C-skeletonsmentioning

confidence: 99%

Intermolecular Allene–Alkyne Coupling: A Significantly Useful Synthetic Transformation

Pradhan,

Park

2024

ACS Catal.

View full text Add to dashboard Cite

show abstract

“…[ 27 ] Recently, Naidu and Bäckvall developed an efficient oxidative annulation reaction for the synthesis of functionalized polyenes between yne‐allenes 7 and enallenes 8 (Scheme 3a). [ 28 ] This palladium‐catalyzed intermolecular carbocyclization cascade in CH 3 CN at 80°C provides a wide variety of interesting polyene products 9 in high yield (up to 90%) and with excellent regio‐ and stereoselectivities by using 1,4‐benzoquinone (BQ) as the oxidant. The reaction also tolerated aerobic conditions with catalytic amount of BQ together with Co(salophen).…”

Section: Synthesis Of Carbocyclesmentioning

confidence: 99%

Engaging Yne‐Allenes in Cycloaddition Reactions: Recent Developments

Wang

Hao

et al. 2022

Chin. J. Chem.

View full text Add to dashboard Cite

Comprehensive Summary Yne‐allenes bearing both a C—C triple bond and an allene unit are a class of focal substrates in organic synthesis, in view of their structure diversity, high reactivity and intermediate variety in the past years. Engaging yne‐allenes in numerous annulation cascades provides efficient and direct accesses to elaborate functionalized polycyclic molecular architectures in a convergent manner. There are lots of types of catalytic chemical reactions such as intramolecular cyclizations, cycloisomerizations, intermolecular annulations, and bicyclizations as well as tricyclizations with the assistance of Lewis acids, Brønsted acids, bases, transition metals, and other catalysts. This review provides an overview of the chemistry developed with transformations of yne‐allenes by discussing their general and specific reactivities, presenting and commenting on their mechanisms as well as their applications.

show abstract

“…In the palladium-catalyzed allylic C–H oxidation reaction, early studies on cyclic or acyclic alkenes by the group of Åkermark, Bäckvall, White, and Shi showed that the reactions proceed via π-allylpalladium(II) intermediates generated through allylic C–H bond cleavage. However, reports on the dendralene synthesis involving C–H bond cleavage are scarce . In particular, we were inspired by Bäckvall and co-workers who reported a straightforward synthesis of [3]dendralene derivatives through palladium-catalyzed allenic C–H bond oxidation (Scheme d) .…”

mentioning

confidence: 99%

Palladium-Catalyzed Oxidative Coupling of the Allenic C–H Bond with α-Diazo Esters: Synthesis of [3]Dendralenes

Hou

Wang

2021

J. Org. Chem.

View full text Add to dashboard Cite

A palladium-catalyzed highly regio-and stereoselective allenic C−H oxidative coupling with α-diazo esters is developed. The reaction pathway involves allylic palladium carbene as the key intermediate, which is followed by a carbene migratory insertion process. The reaction proceeds efficiently under mild conditions without external base, providing substituted [3]dendralenes bearing various functional groups.

show abstract

Synthesis of Cross-Conjugated Polyenes via Palladium-Catalyzed Oxidative C–C Bond Forming Cascade Reactions of Allenes

Cited by 8 publications

References 48 publications

Intermolecular Allene–Alkyne Coupling: A Significantly Useful Synthetic Transformation

Intermolecular Allene–Alkyne Coupling: A Significantly Useful Synthetic Transformation

Engaging Yne‐Allenes in Cycloaddition Reactions: Recent Developments

Palladium-Catalyzed Oxidative Coupling of the Allenic C–H Bond with α-Diazo Esters: Synthesis of [3]Dendralenes

Contact Info

Product

Resources

About