1429478-69-2Relevant academic research and scientific papers
Regiodivergent C?H and Decarboxylative C?C Alkylation by Ruthenium Catalysis: ortho versus meta Position-Selectivity
Ackermann, Lutz,Korvorapun, Korkit,Messinis, Antonis M.,Moselage, Marc,Rogge, Torben,Struwe, Julia
supporting information, p. 18795 - 18803 (2020/08/27)
Ruthenium(II)biscarboxylate complexes enabled the selective alkylation of C?H and C?C bonds at the ortho- or meta-position. ortho-C?H Alkylations were achieved with 4-, 5- as well as 6-membered halocycloalkanes. Furthermore, the judicious choice of the directing group allowed for a full control of ortho-/meta-selectivities. Detailed mechanistic studies by experiment and computation were performed and provided strong support for an oxidative addition/reductive elimination process for ortho-alkylations, while a homolytic C?X cleavage was operative for the meta-selective transformations.
Meta-Selective C-H bond alkylation with secondary alkyl halides
Hofmann, Nora,Ackermann, Lutz
supporting information, p. 5877 - 5884 (2013/06/04)
Ruthenium catalysts enabled C-H bond functionalizations on arenes with challenging secondary alkyl halides. Particularly, ruthenium(II) biscarboxylate complexes proved to be the key to success for direct alkylations with excellent levels of unusual meta-selectivity. The direct alkylations occurred under mild reaction conditions with ample scope and tolerated valuable functional groups. Detailed mechanistic studies were performed, including various competition experiments as well as reactions with isotopically labeled substrates. These studies provided strong support for an initial reversible cyclometalation. The cycloruthenation thereby activates the arene for a subsequent remote electrophilic-type substitution with the secondary alkyl halides. Independently prepared cycloruthenated complexes were found to be catalytically active provided that a carboxylate ligand was present, thereby highlighting the key importance of carboxylate assistance for effective meta-selective C-H bond alkylations.
