Synthesis of Functionalized 4,1‐Benzothiazepines via a [4+3] Annulation between Aza‐
<i>o‐</i>
Quinone Methides and Pyridinium 1,4‐Zwitterionic Thiolates
The [4+3] annulation of aza-o-quinone methides and pyridinium1,4-zwitterionicthiolates has been developed for the one-step synthesis of functionalized 2,3-unsaturated 4,1-benzothiazepines under mild and metal-free conditions. The produced 4,1-benzothiazepines can easily be converted into biologically interesting sulfoxides and sulfones via selective oxidization with m-CPBA.
Enantioselective Annulations for Dihydroquinolones by in Situ Generation of Azolium Enolates
作者:Anna Lee、Ashkaan Younai、Christopher K. Price、Javier Izquierdo、Rama K. Mishra、Karl A. Scheidt
DOI:10.1021/ja505880r
日期:2014.7.30
A convergent, catalytic asymmetric formal [4 + 2] annulation for the synthesis of dihydroquinolones has been developed. Carboxylic acids can be employed as precursors to NHC enolates through an in situ activation strategy. Simultaneous generation of a reactive aza-o-quinone methide under the basic conditions employed for NHC generation leads to a dual activation approach.
DMAP-Catalyzed [4+3] Spiroannulation of Pyrazolone-Derived Morita–Baylis–Hillman Carbonates with <i>N</i>-(<i>o</i>-Chloromethyl)aryl Amides to Forge Spiro[pyrazolone-azepine] Scaffolds
作者:Xingfu Wei、Yue Huang、Zahra Karimi、Jingping Qu、Baomin Wang