Carbon−Nitrogen Bond-Forming Reactions of Palladacycles with Hypervalent Iodine Reagents

Abstract

Palladium(II) complexes containing bidentate cyclometalated C∼N chelating ligands are shown to react with PhINTs at room temperature to insert “NTs” into the Pd−C bond. This “NTs” insertion reaction has been applied to palladacyclic complexes of azobenzene, benzo[h]quinoline, and 8-ethylquinoline. The newly aminated organic ligands can be liberated from the metal center by protonolysis with trifluoroacetic acid or HCl.

Palladium‐Catalyzed Oxidative sp2 CH Bond Acylation with Aldehydes

“…The planar geometry of 4 is considered to be responsible for the high efficiency of the metal-catalyzed C À H bond functionalization generally observed. [9] In fact, good yields were obtained for all aliphatic aldehyde substrates. Acetaldehyde was also coupled with high efficiency under the described conditions.…”

Palladium‐Mediated Fluorination of Arylboronic Acids

“…Our design was based on the assumptions that nitrogenous ligands resist oxidation by electrophilic fluorination reagents, can support highvalent aryl palladium fluorides for subsequent carbon-fluorine reductive elimination, and do not induce competing nitrogenfluorine reductive elimination. We prepared the new palladium acetate complex 1 by known sulfonamide insertion [23] into the palladium-carbon bond of benzoquinoline-derived palladacycle 3, [24] followed by chloride-acetate ligand exchange (eq 2). The aryl palladium complexes 4a-m were prepared by transmetallation using 12 different arylboronic acids (Table 1).…”

Palladium-Catalyzed Group-Directed sp2-C—H Functionalization

“…[29] 还对反应机理进行 了深入的研究, 进一步证实了通过还原消除生成的 而且 Sanford 课题组 [33] 也通过机理研究证实了氮卡 宾的确是可以插入 C-Pd 键的(Scheme 6). 此后, 该课题组 [36] 又对吡啶导向的 C-X 键的形成 做了一系列机理的研究, 具体不再介绍.…”