Visible-light-mediated selective thiocyanation/ipso-cyclization/oxidation cascade for the synthesis of thiocyanato-containing azaspirotrienediones
作者:Yuan Chen、Yu-Jue Chen、Zhi Guan、Yan-Hong He
DOI:10.1016/j.tet.2019.130763
日期:2019.12
visible-light-mediated metal-free thiocyanate radicaladdition/ipso-cyclization/oxidation cascade reaction for the synthesis of thiocyanato-containing azaspirotrienediones from N-phenylpropynamides is described. Cheap and readily available ammonium thiocyanate was used as a precursor to the thiocyanate freeradical, which undergoes a radicaladditionreaction with the alkyne, followed by selective ipso-cyclization
Copper-Catalyzed Difunctionalization of Activated Alkynes by Radical Oxidation-Tandem Cyclization/Dearomatization to Synthesize 3-Trifluoromethyl Spiro[4.5]trienones
A copper‐catalyzed difunctionalizing trifluoromethylation of activated alkynes with the cheap reagent sodium trifluoromethanesulfinate (NaSO2CF3 or Langlois’ reagent) has been developed incorporating a tandem cyclization/dearomatization process. This strategy affords a straightforward route to synthesis of 3‐(trifluoromethyl)‐spiro[4.5]trienones, and presents an example of difunctionalization of alkynes
Silver-catalyzed direct spirocyclization of alkynes with thiophenols: a simple and facile approach to 3-thioazaspiro[4,5]trienones
作者:Huanhuan Cui、Wei Wei、Daoshan Yang、Jimei Zhang、Zhihong Xu、Jiangwei Wen、Hua Wang
DOI:10.1039/c5ra16548b
日期:——
A new and convenient silver-catalyzed direct oxidative spirocyclization of alkynes with thiophenols is described. This methodology provides a simple and practical approach to various 3-thioazaspiro[4,5]trienones in moderate to good yields with high atom efficiency and excellent functional group tolerance.
Catalytic oxidation/C–H functionalization of N-arylpropiolamides by means of gold carbenoids: concise route to 3-acyloxindoles
作者:Deyun Qian、Junliang Zhang
DOI:10.1039/c2cc31972a
日期:——
An efficient catalytic CâH functionalization by means of gold carbenoids for the one-step synthesis of 3-acyloxindole derivatives has been developed. The reaction proceeds efficiently with extremely good substrate scope and significant opportunities for structural diversification.
Photoredox‐Catalyzed Tandem Demethylation of
<i>N</i>
,
<i>N</i>
‐Dimethyl Anilines Followed by Amidation with α‐Keto or Alkynyl Carboxylic Acids
作者:Pritha Das、Hasina Mamataj Begam、Samir Kumar Bhunia、Ranjan Jana
DOI:10.1002/adsc.201900525
日期:2019.9.3
for highly selective monodemethylation of N,N‐dimethyl anilines to generate secondary amines and subsequent coupling with α‐ketocarboxylic acids or alkynyl carboxylic acids to form α‐ketoamides or alkynamides respectively undervisiblelight photoredox catalyst in a single operation. From the deuterium‐labeling experiment, it was probed that demethylation is the slowest step in this tandem process