Ruthenium(II)‐Catalyzed CH Activation with Isocyanates: A Versatile Route to Phthalimides

Abstract

A cationic ruthenium(II)-complex was utilized in the efficient synthesis of phthalimide derivatives by C-H activation with synthetically useful amides. The reaction proceeded through a mechanistically unique insertion of a cycloruthenated species into a C-Het multiple bond of isocyanate. The novel method also proved applicable for the synthesis of heteroaromatic unsymmetric diamides as well as a potent COX-2 enzyme inhibitor.

Transition-Metal-Catalyzed C–H Bond Addition to Carbonyls, Imines, and Related Polarized π Bonds

“…126 Cationic Ru(II) was generated in situ from [RuCl 2 ( p -cymene)] 2 /AgSbF 6 and pyrrolidine amide was employed as the directing group for this reaction. Pyrrolidine benzamides with halides and donating groups at the para -position provided phthalimides in 44–82% yield.…”

Ruthenium‐Catalyzed Synthesis of Heterocycles via CH Bond Activation

“…(7.57)) [66]. This method is applicable to generate a potent COX-2 enzyme inhibitor in step-economical way.…”

Heterogeneous Catalytic Oxidation of Amides to Imides by Manganese Oxides

“…Traditionally imides have been synthesized by reaction between dicarboxylic acid e.g., phthalic acid (or anhydride) and amines 3 . Acylation of amides 4 , and rearrangement of isocyanates can also yield imides 5 . A few homogeneous catalytic oxidations of amides to imides are reported recently using organic hydroperoxides as terminal oxidants 6 – 8 .…”