C–H Functionalization of Cyclopropanes: A Practical Approach Employing a Picolinamide Auxiliary

A Pd-catalyzed, picolinamide-enabled, and efficient C–H arylation of cyclopropanes is described. The reaction can be promoted by either a silver additive or catalytic pivalic acid in the presence of a carbonate base. Various aryl iodides can be employed as coupling partners, providing exclusively <i>cis</i>-substituted cyclopropylpicolinamides

Silver-Promoted, Palladium-Catalyzed Direct Arylation of Cyclopropanes: Facile Access to Spiro 3,3′-Cyclopropyl Oxindoles

The Pd-catalyzed, Ag(I)-mediated intramolecular direct arylation of cyclopropane C–H bonds is described. Various spiro 3,3′-cyclopropyl oxindoles can be obtained in good to excellent yields from easily accessible 2-bromoanilides. The kinetic isotope effect was determined and epimerization studies were conducted, suggesting that the formation of a putative Pd-enolate is not operative and that the reaction proceeds via a C–H arylation pathway

Transition-Metal-Free Amination of Pyridine-2-sulfonyl Chloride and Related <i>N</i>‑Heterocycles Using Magnesium Amides

A new transition-metal-free amination of pyridine-2-sulfonyl chloride and related <i>N</i>-heterocycles using magnesium amides of type R₂NMgCl·LiCl is reported. Additionally, the directed <i>ortho</i>-magnesiation of pyridine-2-sulfonamides using TMPMgCl·LiCl was investigated. Reaction of the magnesium intermediates with various electrophiles and subsequent amination using magnesium amides led to a range of 2,3-functionalized pyridines. Also, cyclization reactions providing an aza-indole and an aza-carbazole were carried out