Trifluoroacetylation of amines with trifluoroacetic acid in the presence of trichloroacetonitrile and triphenylphosphine
作者:Joong-Gon Kim、Doo Ok Jang
DOI:10.1016/j.tetlet.2009.11.105
日期:2010.1
We developed a mild and convenient trifluoroacetylation process for amines using a combination of trichloroacetonitrile and triphenylphosphine. The reaction that we designed is applicable to the trifluoroacetylation of a wide variety of amines, including amines with stereogenic centers, which underwent trifluoroacetylation without racemization.
Remote Regioselective Radical C–H Functionalization of Unactivated C–H Bonds in Amides: The Synthesis of <i>gem</i>-Difluoroalkenes
作者:Qu-Ping Hu、Jing Cheng、Ying Wang、Jie Shi、Bi-Qin Wang、Ping Hu、Ke-Qing Zhao、Fei Pan
DOI:10.1021/acs.orglett.1c01385
日期:2021.6.4
The site-selective functionalization of unactivated aliphatic amines is an attractive and challenging synthetic approach. We herein report a general strategy for the remote site-selective functionalization of unactivated C(sp3)–H bonds in amides by photogenerated amidyl radicals to form gem-difluoroalkenes with trifluoromethyl-substituted alkenes. The site selectivity is controlled by a 1,5-hydrogen
Triphenylantimony dicarboxylates (Ph3Sb(O2CR)2, where R=Me, CF3, Ph and CH2NH-Z) readily reacted with amines (R′NH2, where R′=n-C6H13, s-Bu, C6H11, and Ph) to afford corresponding amides and triphenylstibine oxide in fairly good yields. The amidation of RCO2H with R′NH2 was also catalyzed by the orgnoantimony compounds.
new trifluoroacetylating reagent, 2-(trifluoroacetyloxy)pyridine (TFAP), was prepared by the reaction of 2-pyridinol and trifluoroacetic anhydride. TFAP has been found to be effective in the trifluoroacetylation of aliphatic and aromatic amines and alcohols including phenol under mild conditions. The reaction of p-nitrophenol with TFAP in ether gave the hydrogen-bonded complex between the phenol and
Regioselective Alkylative Cross-Coupling of Remote Unactivated C(<i>sp</i><sup>3</sup>)–H Bonds
作者:Scott M. Thullen、Sean M. Treacy、Tomislav Rovis
DOI:10.1021/jacs.9b07014
日期:2019.9.11
The functionalization of unactivatedC(sp3)-H bonds poses a significant challenge due to their ubiquity and relative similarity in most organic frameworks. Herein, we describe the use of a combined photoredox and nickel catalytic system for the regioselective C(sp3)-C(sp3) coupling of unactivatedC(sp3)-H bonds and alkyl bromides. Positional selectivity is dictated by a 1,5-hydrogen atom transfer (HAT)