TMSOTf-mediated approach to 1,3-oxazin-2-one skeleton through one-pot successive reduction-[4 + 2] cyclization process of imides with ynamides
作者:Chen-Chen Zhang、Zhi-Peng Huo、Mei-Lin Tang、Yong-Xi Liang、Xun Sun
DOI:10.1016/j.tetlet.2021.152946
日期:2021.3
A one-pot approach to access functionalized 1,3-oxazin-2-one skeleton has been developed through successive reduction and subsequent [4 + 2] cyclization process of N-Boc lactams with ynamides by TMSOTf. As a result, a number of five to seven membered ring fused bicyclic [1,2-c][1], [3]oxazin-1-ones 12a-m and tricyclic derivatives 13a-f were obtained in moderate to excellent yields with excellent regioselectivities
Gold(III)-Catalyzed Formal [3 + 2] Annulations of <i>N</i>-Acyl Sulfilimines with Ynamides for the Synthesis of 4-Aminooxazoles
作者:Xianhai Tian、Lina Song、Chunyu Han、Cheng Zhang、Yufeng Wu、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1021/acs.orglett.9b01011
日期:2019.4.19
A gold-catalyzed formal 1,3-dipolar [3 + 2] annulation using readily accessible N-acyl sulfilimines and ynamides is reported. This reaction includes the cleavage of a N–S bond and subsequent C–O bond formation. In total, 30 oxazole derivatives bearing diverse functionalities could be prepared in 43–98% yield from the corresponding sulfilimines and ynamides.
vinyl dichlorides and electron deficient amides as the starting material is described. In the absence of transition-metal catalyst, the reaction proceeds under mild reaction conditions in open air and thus rendering a convenient operation. This strategy is not only suitable for both terminal and internal ynamide synthesis but also amenable for large-scale preparation. Broad substrate scopes with respect
Chemoselective Deprotection of Sulfonamides Under Acidic Conditions: Scope, Sulfonyl Group Migration, and Synthetic Applications
作者:Tomas Javorskis、Edvinas Orentas
DOI:10.1021/acs.joc.7b02507
日期:2017.12.15
Chemoselective acidic hydrolysis of sulfonamides with trifluoromethanesulfonic acid has been evaluated as a deprotection method and further extended to more complex synthetic applications. In contrast to conventional troublesome sulfonamide hydrolysis, a near-stoichiometric amount of acid was found to be sufficient to bring about efficient deprotection of various neutral or electron-deficient N-arylsulfonamides
The synthesis of ynamides in water was achieved by a micellarcatalysis strategy using rosin‐based surfactant APGS‐550‐M, which can be easily prepared from natural abundant biomass.