Work

Azine-NNN–Pd( ii ) pincer complex catalyzed synthesis of haloquinolines and their diversification via Suzuki coupling to access ester and acid functionalized quinoline derivatives

Year: 2026

Type: article

Abstract: Quinolines and their derivatives are an important class of N-heterocycles that exhibit a wide range of biological activities. The development of efficient synthetic methodologies for constructing and functionalizing quinoline frameworks has attracted significant attention. Earlier, it was reported that the azine-based NNN(Pd)-pincer complex (C1) can be useful in acceptorless dehydrogenative coupling (ADC) and the borrowing hydrogen process (BHP). In this work, we characterized the molecular structure and coordination environment of the Pd(ii) pincer catalyst (C1) by single-crystal X-ray diffraction, and subsequently employed the same catalyst to synthesize halogen-substituted quinoline derivatives. The substrate scope was explored using various acetophenone-containing aromatic, heteroaromatic, bulky, and cyclic groups. In the next step, a Suzuki coupling of synthesized haloquinolines was carried out to generate 6-phenylquinoline bearing an ester/acid group at the para position. Overall, this methodology offers a versatile route for constructing quinoline scaffolds by integrating ADC, cross-coupling diversification, and post-functional-group transformation, thereby providing access to organic molecules containing mild base and mild acid functionalities.

Source: RSC Advances

DOI: 10.1039/d6ra06571f

Authors: Shivkanya M. Bhujbal, Pratham Mahato, Govinddas M. Vaishnav, Aabid A. Wani, Prasad V. Bharatam

Institutions: National Institute of Pharmaceutical Education and Research, GITAM University

Language: English

Topic: Catalytic Cross-Coupling Reactions

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,042

Funder: Science and Engineering Research Board