Iodine-promoted cyclization of N-propynyl amides and N-allyl amides via sulfonylation and sulfenylation
作者:Gopal Chandru Senadi、Bing-Chun Guo、Wan-Ping Hu、Jeh-Jeng Wang
DOI:10.1039/c6cc05138c
日期:——
Iodine-promoted sulfonylation of N-propynyl amides with sulfonyl hydrazides followed by DBU mediated cyclisation to afford 5-methyl-arylsulfonyloxazoles and oxysulfenylation of N-allyl amides through electrophilic addition of in situ generated sulfenyl iodide...
Continuous Flow Sonogashira C–C Coupling Using a Heterogeneous Palladium–Copper Dual Reactor
作者:Li-Min Tan、Zhi-Yu Sem、Wei-Yuan Chong、Xiaoqian Liu、Hendra、Wei Lek Kwan、Chi-Lik Ken Lee
DOI:10.1021/ol303046e
日期:2013.1.4
We report the development of a heterogeneous catalyst system on continuousflow chemistry. A palladium (Pd) coated tubular reactor was placed in line with copper (Cu) tubing using a continuousflow platform, and a Sonogashira C–C coupling reaction was used to evaluate the performance. The reactions were favorably carried out in the Cu reactor, catalyzed by the traces of leached Pd from the Pd reactor
6-endo-dig cyclization of propargylic amides, using N-bromosuccinimide (NBS) as an electrophilic source. The metal-free reaction can be conducted under mild conditions with good functional group compatibility, delivering excellent yields of the desired products. Mechanistic studies suggest that the reaction proceeds via a double electrophilic attack by NBS on the propargylic amide substrate.
Iodoarene-catalyzed cyclizations of <i>N</i>-propargylamides and β-amidoketones: synthesis of 2-oxazolines
作者:Somaia Kamouka、Wesley J Moran
DOI:10.3762/bjoc.13.177
日期:——
Two complementary iodoarene-catalyzed methods for the preparation of 2-oxazolines are presented. The first involves the cyclization of N-propargylamides and the second involves the cyclization of β-amidoketones. These are proposed to proceed through different mechanisms and have different substrate scopes.