Palladium(II)-Catalyzed Direct Alkenylation and Arylation of Arenes: Removable 2-Pyridylsulfinyl Group Assisted C–H Bond Activation

Abstract

Palladium-catalyzed C-H activation reactions directed by a removable 2-pyridylsulfinyl group were developed. Aromatic olefination products were formed in good yields on treatment of 2-(phenylsulfinyl)pyridines with alkenes in the presence of a Pd catalyst. The reaction tolerates a wide range of substituted alkenes, including various acrylates and styrenes. The controlled experiments indicated that the 2-pyridyl moiety, rather than the sulfinyl, played the role of ligand. The final reductive desulfonylation affords the stilbenes, sulfides, and disulfides with different reductive conditions, respectively. More importantly, this transformation could also be applied in arylation through dual C-H activation.

Solvent‐Free Ruthenium(II)‐Catalyzed C–H Activation: Synthesis of Alkenylarylpyrazole Derivatives

“…However, the oxidative alkenylation of heteroarenes is named the Moritani-Fujiwara reaction. [8,9] In this regard, different palladium [10][11][12][13] and rhodium catalysts [14][15][16] have already been used to promote the oxidative alkenylation of heteroarenes with a variety of directing groups, namely, imines, [17,18] amines, [19] and carboxylates. [20,21] Rutheniumcatalyst-directed arylation of unactivated C-H bonds with phenols was reported by Ackermann.…”

C−H Coupling Reactions Directed by Sulfoxides: Teaching an Old Functional Group New Tricks

“…Zhang and co-workers showed that such intermediates enable the C À H/C À H coupling of arenes 30 with electron-deficient alkenes,s tyrenes,a nd arenes (Scheme 13 C). [25,26] Furthermore,t he 2-pyridylsulfinyl directing group has also been employed by Arrayµs,F ernµndez-Ibµnez, Carretero,a nd co-workers to mediate aP d II -catalyzed C À Hc oupling of 30 with methylboronic acid and aryl boronic acid neopentyl esters (Scheme 13 D). [27] Antonchick and Samanta employed as ulfoxide as the directing group in ap owerful Pd-catalyzed triple CÀH activation approach for the conversion of aryl benzyl sulfoxides 33 into important dibenzothiophenes 34.…”

Sulfoxid‐gelenkte C‐H‐Kupplungsreaktionen: Eine alte funktionelle Gruppe lernt neue Tricks

“…Zhang und Mitarbeiter zeigten, dass derartige Intermediate eine C-H/C-H-Kupplung der Arene 30 mit elektronenarmen Alkenen, Styrolen und Arenen ermçglichen (Schema 13 C). [25,26] Darüber hinaus wurde die 2-Pyridylsulfinyl-Gruppe von Arrayµs,F ernµndez-Ibµnez, Carretero und Mitarbeitern als dirigierende Gruppe eingesetzt, um eine Pd II -katalysierte C-H-Kupplung von 30 mit Methylboronsäure und Arylboronsäureneopentylestern zu vermitteln (Schema 13 D). [27] Antonchick und Samanta gebrauchten ein Sulfoxid als lenkende Gruppe in einer beeindruckenden Pd-katalysierten dreifachen C-H-Aktivierung,welche die Arylbenzylsulfoxide 33 in die wichtigen Dibenzothiophene 34 umwandelt.…”