Remote C–H bond functionalization reveals the distance-dependent isotope effect
作者:Jiao-Jie Li、Ramesh Giri、Jin-Quan Yu
DOI:10.1016/j.tet.2008.03.026
日期:2008.7
Iodination of remote aryl C-H bonds has been achieved using palladium acetate as the catalyst and iodoacetate (IOAc) as the oxidant. Systematic kinetic isotope studies imply a mechanistic regime shift as the number of bonds separating the directing heteroatom and the target C-H bond increases. Both isotope and electronic effects observed in remote C-H bond activation are consistent with an electrophilic palladation pathway in which the initial palladation is slower than the C-H bond cleavage. (C) 2008 Elsevier Ltd. All rights reserved.
Palladium(II)-Catalyzed C(sp<sup>2</sup>)–H Bond Activation/C–N Bond Cleavage Annulation of <i>N</i>-Methoxy Amides and Arynes
The Pd(II)-catalyzedC–Hbond activation/C–Nbond cleavage annulation reaction of N-alkyoxyamide aryne is developed to synthesize 9,10-dihydrophenanthrenone derivatives. This reaction exhibited good functional group compatibility with yields up to 92%. Detailed mechanistic studies showed that the key to C–Nbond cleavage is the formed eight-membered palladacycle intermediate undergoing nucleophilic