Palladium-catalyzed Direct Alkenylation Research Articles

Synthesis of alkenylated tetrathienoacenes obtained by palladium catalyzed direct C–H alkenylations

The palladium-catalyzed direct alkenylation of alkyl chain-substituted tetrathienoacenes has been developed under mild conditions. This effective and feasible approach could be readily applied to a variety of dialkenylated tetrathienoacenes using different functionalized alkenes as the coupling substrates, such as linear α,β-unsaturated esters, alkenyl phosphonate, sulfone, acrolein, asn styrene derivatives.

Correction to “Access to Cyclopropyl-Fused Azacycles via a Palladium-Catalyzed Direct Alkenylation Strategy”

ADVERTISEMENT RETURN TO ARTICLES ASAPPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to “Access to Cyclopropyl-Fused Azacycles via a Palladium-Catalyzed Direct Alkenylation Strategy”Carolyn L. LaddCarolyn L. LaddMore by Carolyn L. Ladd and André B. Charette*André B. CharetteMore by André B. Charettehttps://orcid.org/0000-0001-5622-5063Cite this: Org. Lett. 2022, XXXX, XXX, XXX-XXXPublication Date (Web):June 16, 2022Publication History Received2 June 2022Published online16 June 2022https://doi.org/10.1021/acs.orglett.2c01874© 2022 American Chemical SocietyRIGHTS & PERMISSIONSACS AuthorChoiceArticle Views374Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (398 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Access to Cyclopropyl-Fused Azacycles via a Palladium-Catalyzed Direct Alkenylation Strategy.

Palladium-catalyzed direct alkenylation of cyclopropyl C-H bonds proceeds in high efficiency. This transformation provides access to novel cyclopropyl-fused azacycles. Ligand studies suggest that bisphosphine monoxide analogues of dppf and rac-BINAP are the active ligand species. Preliminary results support that both BozPhos and IPrMonophos ligands can achieve high enantioinduction for this novel direct alkenylation reaction. To date, this represents the first example of enantioselective C-H functionalization employing a bisphosphine monoxide ligand.

ChemInform Abstract: Palladium(II)‐Catalyzed Direct C—H Alkenylation of Thienothiophene and Related Fused Heteroarenes.

The palladium-catalyzed direct alkenylation of thieno[3,2-b]thiophene takes place regioselectively at C2. Symmetrically and unsymmetrically 2,5-dialkenylated thienothiophene derivatives can be prepared by the catalytic procedure. Related fused thienyl and carbazole derivatives also undergo regioselective direct alkenylation.

Palladium-catalyzed direct alkenylation of 4-hydroxy-2-pyridones

The first direct 3-alkenylation of N-substituted 4-hydroxy-2-pyridones with unactivated alkenes is reported through a palladium acetate catalyzed, oxidative coupling.

Palladium(II)-Catalyzed Direct C-H Alkenylation of Thienothiophene and Related Fused Heteroarenes.

The palladium-catalyzed direct alkenylation of thieno[3,2-b]thiophene takes place regioselectively at C2. Symmetrically and unsymmetrically 2,5-dialkenylated thienothiophene derivatives can be prepared by the catalytic procedure. Related fused thienyl and carbazole derivatives also undergo regioselective direct alkenylation.

Palladium-catalyzed direct alkenylation of 2-methyl-4H-pyrido[1,2-a]pyrimidin-4-ones using oxygen as the oxidant

A direct C-3 alkenylation of 2-methyl-4H-pyrido[1,2-a]pyrimidin-4-ones through palladium-catalyzed C–H activation using oxygen as the terminal oxidant has been developed.

Highly regioselective palladium-catalyzed direct alkenylation of thiazolo[3,2-b]-1,2,4-triazoles via C[sbnd]H activation

An efficient and regioselective palladium-catalyzed oxidative cross-coupling reaction between thiazolo[3,2-b]-1,2,4-triazoles and alkenes has been developed. This protocol provides easy access to a variety of functionalized thiazolo[3,2-b]-1,2,4-triazole derivatives.

Palladium-Catalyzed Direct Alkenylation of 2-Oxazolones: An Entry to 3,4,5-Trisubstituted 2-Oxazolones

Described herein is a novel method for the synthesis of 3,4,5-trisubstituted 2-oxazolones featuring the first Pd-catalyzed dehydrogenative alkenylation of 2-oxazolones, which is realized by employing 10 mol % of Pd(OAc)2 as the catalyst and the use of readily available Cu(OAc)2 as the oxidant. A wide range of functional groups, such as F, Cl, Br, OMe, ester, ketone, amide, alkyl, and aryl substituents, are found to be compatible under the reaction conditions. The utilization of the C-H functionalization strategy provides a straightforward, convenient, and highly atom-economical approach for the construction of 3,4,5-trisubstituted 2-oxazolones. It is worth noting that the 4-alkenyl 2-oxazolones can be smoothly converted into naphtho[1,2-d]oxazol-2-ones via a photochemical transformation.

Synthesis of 2-Substituted Pyrazolo[1,5-a]pyridines through Cascade Direct Alkenylation/Cyclization Reactions

The synthesis of 2-substituted pyrazolo[1,5-a]pyridines from N-iminopyridinium ylides is described. These medicinally interesting compounds are formed through a cascade process involving a palladium-catalyzed direct alkenylation reaction followed by silver-mediated cyclization. The reaction can be performed with a wide range of electron-poor and electron-rich alkenyl iodides in good yields. This work represents perhaps the most direct route for the preparation of these compounds.