Work

Rh(III)-Catalyzed Regioselective [4 + 2] Annulation of 2-Benzyl-2H-indazole-6-carboxylic Acids with Ynamides to Access Indazole-Fused Pyrans

Year: 2025

Type: article

Abstract: -indazole-6-carboxylic acids with ynamides, enabling the regioselective synthesis of indazole-fused pyrans. Mechanistic studies highlight the pivotal role of the dual directing groups (indazole and carboxylic acid) in facilitating selective C7-H bond activation, even in the presence of the competing C5-H bond. This method provides a straightforward and efficient approach for accessing structurally diverse indazole-fused pyran derivatives under mild reaction conditions. In the photoluminescence study, the synthesized compounds exhibited tunable fluorescence (410-520 nm), covering most of the visible spectrum, along with a positive solvatochromic shift in solvents of varying polarity.

Source: The Journal of Organic Chemistry

DOI: 10.1021/acs.joc.5c02242

Authors: Hung-Sheng Hsieh, Kuan-Miao Liu, Chi-Min Chao, Indrajeet J. Barve, Chung-Ming Sun

Institutions: National Yang Ming Chiao Tung University, Chung Shan Medical University, Chung Shan Medical University Hospital, Abasaheb Garware College, Kaohsiung Medical University

Language: English

Topic: Catalytic C–H Functionalization Methods

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: Ministry of Science and Technology, Taiwan, National Science and Technology Council