Copper‐Catalyzed Successive C−C bond formations on Indoles or Pyrrole: A Convergent Synthesis of Symmetric and Unsymmetric Hydroxyl Substituted N‐H Carbazoles

Abstract

A novel copper-catalyzed successive CÀCbond formations on indoles and pyrrole approach for the direct synthesis of hydroxyl substituted N-H carbazoles is described. The current process represents an atom-economical method for the preparation of both symmetric and unsymmetric densely substituted and hydroxyl containing N-H carbazoles from easily accessible starting materials without the need for expensive metals and harsh reaction conditions.

Recent synthetic strategies for the construction of functionalized carbazoles and their heterocyclic motifs enabled by Lewis acids

“…This simple Lewis acid system provides important features for the synthesis of annulated carbazole derivatives in good to high yields, including toleration of functional groups such as F, Cl, Br, I, Me, OMe, COMe, NO 2 , etc., under sustainable conditions. 129 The group of Mohanakrishnan and colleagues in 2013 examined the Lewis acid-mediated thermal cyclization of the enamine 66 was then carried out using different Lewis acids, such as ZnBr 2 , CuBr 2 , InBr 3 , CeCl 3 , and FeCl 3 , and the obtained results are cited in Scheme 46. In general, the preparation of carbazole 67 was found to be successful with various Lewis acids.…”

Synthesis of Spirooxindoles from N-Arylamide Derivatives via Oxidative C(sp2)–C(sp3) Bond Formation Mediated by PhI(OMe)2 Generated in Situ

“…Carbon–carbon bond-forming reactions play a very important role in organic synthesis . Hypervalent iodine reagents have also been vastly applied to the construction of C­(sp 2 )–C­(sp 2 ) and C­(sp 2 )–C­(sp) bonds under metal-free conditions.…”