Thiocarbamate-Directed Tandem Olefination–Intramolecular Sulfuration of Two <i>Ortho</i> C–H Bonds: Application to Synthesis of a COX-2 Inhibitor
作者:Wendong Li、Yingwei Zhao、Shaoyu Mai、Qiuling Song
DOI:10.1021/acs.orglett.8b00089
日期:2018.2.16
A palladium-catalyzed dual ortho C–H bond activation of aryl thiocarbamates is developed. This tandem reaction initiates by thiocarbamate-directed ortho C–H palladation, which leads to favorable olefin insertion rather than reductive elimination. The oxidative Heck reaction followed by another C–H activation and sulfuration affords the dual-functionalized products. This reaction provides a concise
Thiocarbamate‐Directed
<i>ortho</i>
C−H Bond Alkylation with Diazo Compounds
作者:Shengnan Jin、Zhan Chen、Yingwei Zhao
DOI:10.1002/adsc.201900804
日期:2019.10.22
We herein report a rhodium catalysed insertion of C(sp2)−H bond into diazo derived carbenes directed by a thiocarbamate group. This reaction provides a direct and efficient pathway to the ortho alkylation of phenol derivatives with a broad substrate scope. The C−H activation process is accomplished through a reversible electrophilic rhodation.
We herein establish a multicomponent annulation method for the synthesis of valuable iminocoumarins using aryl thiocarbamates, internal alkynes, and sulfonamides as starting materials, which are safe and readily available. The key step is a Rh-catalyzed and sulfur-directed C—H bondactivation. Preliminary mechanistic investigations suggested that the nucleophilic attack of the sulfonamide on an active
Studies of the Thiocarbonyl Compounds. III. The Mechanism of the Thermal Rearrangement of Aryl Thionocarboxylates
作者:Aritsune Kaji、Yoshiaki Araki、Koshin Miyazaki
DOI:10.1246/bcsj.44.1393
日期:1971.5
The thermal rearrangement of aryl thionocarboxylates was kinetically investigated in diphenyl ether. The rate constants of the rearrangement of aryl N,N-dimethylthionocarbamates were well correlated with the σ− values, but the plots of the electron-releasing para-substituents deviated slightly on the lower side of the meta correlation line. A good linear free-energy relationship existed between the
A convenient and selective synthesis of alkynylated coumarins from various aryl thiocarbamates and 1,3‐diynes or terminal alkynes via rhodium‐catalyzed C−H bond activation has been developed. In this transformation, both symmetrical and asymmetrical 1,3‐diynes could be applicable, obtaining various 3‐alkynylated coumarins in moderate to excellent yields. When the substituent is aryl group, the resulting