A new method of cobalt-catalyzed synthesis of pyrrolidinones from aliphatic amides and terminal alkynes was discovered through a C-Hbond functionalization process on unactivated sp(3) carbons with the silver cocatalyst using a bidentate auxiliary. For the first time, a broad range of easily accessible alkynes are exploited as the reaction partner in C(sp(3))-H bondactivation to give the important
β-C(sp3)–H bonds of propioamides with organosilanes is described. The reaction proceeds with the assistance of an 8-aminoquinolyl auxiliary in a tandem way by the first oxidation of β-C(sp3)–H bonds and subsequent arylation/vinylation to give the aryloxylation/vinyloxylation products. This unusual aryloxy/vinyloxy forming reaction offers a new avenue for the functionalization of unactivated sp3 C–H
Iron-Catalyzed C(sp<sup>2</sup>)H and C(sp<sup>3</sup>)H Arylation by Triazole Assistance
作者:Qing Gu、Hamad H. Al Mamari、Karolina Graczyk、Emelyne Diers、Lutz Ackermann
DOI:10.1002/anie.201311024
日期:2014.4.7
Modular 1,2,3‐triazoles enabled iron‐catalyzed CHarylations with broad scope. The novel triazole‐based bidentate auxiliary is easily accessible in a highly modular fashion and allowed for user‐friendly iron‐catalyzed C(sp2)H functionalizations of arenes and alkenes with excellent chemo‐ and diastereoselectivities. The versatile iron catalyst also proved applicable for challenging C(sp3)H functionalizations
The nickel-catalyzed beta-thioetherification of unactivated C(sp(3))-H bond of propionamides is established with the assistance of 8-aminoquinoline auxiliary, leading to the beta-thio carboxylic acid derivatives. A broad range of functional groups is compatible with this thioetherfication reaction. The process represents the first successful example of metal-catalyzed C-S bond formation from unactivated C(sp(3))-H bonds.
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.