Cu-Mediated C–H <sup>18</sup>F-Fluorination of Electron-Rich (Hetero)arenes
作者:Matthew S. McCammant、Stephen Thompson、Allen F. Brooks、Shane W. Krska、Peter J. H. Scott、Melanie S. Sanford
DOI:10.1021/acs.orglett.7b01902
日期:2017.7.21
to form a (mesityl)(aryl)iodonium salt. This salt is then used in situ in a Cu-mediated radiofluorination with [18F]KF. This approach leverages the stability and availability of electron-rich arene starting materials to enable mild late-stage radiofluorination of toluene, anisole, aniline, pyrrole, and thiophene derivatives. The radiofluorination has been automated to access a 41 mCi dose of an 18F-labeled
N-Benzyloxy- and N-tert-butoxycarbonyltrifluoromethylsulfonyl-4-trifluoromethylanilides were prepared and were found to be chemoselective and shelf-storable alkoxycarbonylation reagents.
Generation and Alkylation of α-Carbamyl Radicals via Organic Photoredox Catalysis
作者:Joshua B. McManus、Nicholas P. R. Onuska、David A. Nicewicz
DOI:10.1021/jacs.8b04890
日期:2018.7.25
Strategies for the direct C-H functionalization of amines are valuable as these compounds comprise a number of pharmaceuticals, agrochemicals and natural products. This work describes a novel method for the C-H functionalization of carbamate-protected secondary amines via α-carbamyl radicals generated using photoredox catalysis. The use of the highly oxidizing, organic acridinium photoredox catalyst
Facile one-pot synthesis of unsymmetrical ureas, carbamates, and thiocarbamates from Cbz-protected amines
作者:Hee-Kwon Kim、Anna Lee
DOI:10.1039/c6ob01290f
日期:——
A novel one-potsynthesis of unsymmetricalureas, carbamates and thiocarbamates from Cbz-protected amines has been developed. In the presence of 2-chloropyridine and trifluoromethanesulfonyl anhydride, isocyanates are generated in situ, which facilitate rapid reaction with amines, alcohols, and thiols to afford the corresponding ureas, carbamates and thiocarbamates in high yields.
Facile direct synthesis of unsymmetrical ureas from N-Alloc-, N-Cbz-, and N-Boc-protected amines using DABAL-Me3
作者:Soosung Kang、Hee-Kwon Kim
DOI:10.1016/j.tet.2018.06.011
日期:2018.7
A practical synthetic method for the direct synthesis of unsymmetrically substituted ureas from N-Alloc-, N-Cbz-, and N-Boc-protected amines is described. In this study, efficient direct conversion of the Alloc-, Cbz-, and Boc-carbamate compounds to ureas was achieved in the presence of DABAL-Me3, an air stable and easily handled reagent. Using this reaction method, both protected aromatic and aliphatic