N-Perfluoroalkylsulfonylimido derivatives of arenecarboxylic acid amides and their oxidative aza Hofmann rearrangement
摘要:
The analogues of carboxamides in which the sp(2)-hybridized oxygen atom is replaced by more electron-withdrawing groups, =NSO(2)CF(3) and =NSO(2)C(4)F(9), have been synthesized. The resulting N-perfluoroalkylsulfonyl arenecarboxamidines ArC(=NSO(2)R(f))NH(2) (Rf = CF(3), C(4)F(9)) undergo an oxidative Hofmann-type rearrangement to the corresponding carbodiimides ArN=C=NSO(2)R(f) under the action of (diacyloxy-iodo)arenes. Rearrangement of related compounds ArC(=NSO(2)R)NH(2) (R = CH(3), Ph) containing fluorine-free substituents at the sulfonyl group also occurs in similar conditions. It was found that the reactivity of amidines rises with the increasing electron-withdrawing ability of the substituent R. (C) 2008 Elsevier B.V. All rights reserved.
Terminal Alkyne-Assisted One-Pot Synthesis of Arylamidines: Carbon Source of the Amidine Group from Oxime Chlorides
作者:Fengping Yi、Qihui Sun、Jing Sun、Chao Fu、Weiyin Yi
DOI:10.1021/acs.joc.9b00538
日期:2019.6.7
a diverse range of arylamidines from a novel cascade reaction of in situ generated nitrileoxides, sulfonyl azides, terminal alkynes, and water by [3 + 2] cycloaddition and ring opening sequence was developed. The use of aryl oxime chlorides as the carbon source of the amidine group and the addition of water proved to be critical for the reaction. Moreover, terminal alkynes, which can lead to high yields
We report a coupling reaction of thioamides and sulfonyl azides to generate sulfonyl amidines in the absence of any activation additives. The reaction progresses in various solvents under mild conditions. Water exhibits the highest performance with respect to efficiency.