Palladium-Catalyzed [3+3] Annulation between Diarylamines and α,β-Unsaturated Acids through C-H Activation: Direct Access to 4-Substituted 2-Quinolinones

Rajesh Kancherla; Togati Naveen; Debabrata Maiti

doi:10.1002/chem.201500774

Palladium-Catalyzed [3+3] Annulation between Diarylamines and α,β-Unsaturated Acids through C-H Activation: Direct Access to 4-Substituted 2-Quinolinones

Chemistry. 2015 Jun 1;21(23):8360-4. doi: 10.1002/chem.201500774. Epub 2015 Apr 21.

Authors

Rajesh Kancherla¹, Togati Naveen¹, Debabrata Maiti²

Affiliations

¹ Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India).
² Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India). dmaiti@chem.iitb.ac.in.

PMID: 25899388
DOI: 10.1002/chem.201500774

Abstract

A C-H activation strategy has been successfully employed for the high-yielding synthesis of a diverse array of 4-substituted 2-quinolinone species by a palladium-catalyzed dehydrogenative coupling involving diarylamines. This intermolecular annulation approach incorporates readily available α,β-unsaturated carboxylic acids as the coupling partner by suppressing the facile decarboxylation. Based on preliminary mechanistic studies, a reaction sequence is proposed, involving ortho palladation, π-coordination, β-migratory insertion, and β-hydride elimination.

Keywords: CH activation; N heterocycles; annulation; homogeneous catalysis; palladium.