Iridium(III)-Catalyzed Selective and Mild C-H Amidation of Cyclic <i>N</i>
-Sulfonyl Ketimines with Organic Azides
作者:Manikantha Maraswami、Gang Chen、Teck-Peng Loh
DOI:10.1002/adsc.201700785
日期:2018.2.1
A general protocol for iridium catalyzed direct C−H amidation of cyclic N-sulfonyl ketimines using sulfonyl, acyl and arylazides as nitrogen source is reported herein. The reaction takes place at roomtemperature with acyl and arylazides, while an elevated temperature needed with sulfonylazides to furnish aminated sultams in excellent yields with complete chemo and regioselectivity, thus providing
Cobalt‐Catalyzed Transfer Hydrogenation of α‐Ketoesters and
<i>N</i>
‐Cyclicsulfonylimides Using H
<sub>2</sub>
O as Hydrogen Source
作者:Yang Gao、Xuexin Zhang、Ronibala Devi Laishram、Jingchao Chen、Kangkui Li、Keyang Zhang、Guangzhi Zeng、Baomin Fan
DOI:10.1002/adsc.201900636
日期:2019.9.3
A Co‐catalyzed effective transferhydrogenation of various α‐ketoesters and N‐cyclicsulfonylimides by safe and environmentally benign H2O as hydrogensource is described. The reaction used easily available and easy to handle zinc metal as a reductant. Interestingly, the catalytic system does not require ligand for reduction of N‐cyclicsulfonylimides.
Pd<sup>II</sup>
-Catalyzed Spiroannulation of Cyclic <i>N</i>
-Sulfonyl Ketimines with Aryl Iodides through C-H Bond Activation
作者:K. Nagarjuna Reddy、M. V. Krishna Rao、B. Sridhar、B. V. Subba Reddy
DOI:10.1002/ejoc.201700569
日期:2017.8.2
A new strategy has been developed for the first time for the synthesis of spirofluorenyl benzosultams through the annulation of aryl iodides with cyclic N-sulfonyl ketimines. This method involves a readily available Pd(II) catalyst for the activation of aryl C-H bonds to facilitate the annulation process. In contrast, Pd is relatively cheaper than other transition metal catalysts such as Ir and Rh
RhIII-catalyzed aryl C–H vinylation for the preparation of styrenes by using vinylacetate, a commercially available and inexpensive compound, as the vinyl source was successfully realized. This method enables various aromatics including N-sulfonyl ketimines, pyridines, azoles, and amides to be vinylated in moderate to good yields.
Spirocyclic Sultam and Heterobiaryl Synthesis through Rh-Catalyzed Cross-Dehydrogenative Coupling of <i>N</i>-Sulfonyl Ketimines and Thiophenes or Furans
A useful approach is developed for the synthesis of various structurally interesting spirocyclic sultams and heterobiaryls using a cross-dehydrogenative coupling strategy that features high atom and step economy. This method employs [Cp*RhCl2]2 as a catalyst and N-sulfonylimine, a weak coordinating group, as an efficient directing group to assist C–H activation. A number of the coupled products were