Organocatalytic Approach for the Synthesis and Biological Studies of Naphthalene Fluorescent Probe through Hydrogen Transfer Reaction

Abstract

Herein we report an organocatalytic synthesis of highly fluorescent naphthalene derivatives through hydrogen atom transfer featuring neat and mild reaction conditions under air with high substrate tolerance along with atom economy by the unprecedented use of DBU, where oxidation and reduction occurred in one‐pot. Synthesized compounds are utilized in photophysical studies, cytotoxic studies and cell imaging studies of colon cancer cell line CT26.

DBU Promoted Deformylative/Dehalogenative Difunctionalization to Access β‐Bromovinyl Aldehydes Derived from Tetralones**

“…In our previous work, we studied the organo-catalytic behavior of DBU in 1,5 hydrogen atom transfer (HAT) in alkyl(E)-3-(2-formyl3,4-dihydronapthalen-1yl)acrylate for the synthesis of highly fluorescent naphthalene probes. [25] Herein we have developed for the first time a facile and efficient catalyst-/ metal-free DBU promoted deformylative/dehalogenative difunctionalizaton for the transformation of 1-bromo-3,4-dihydronaphthalene-2-carbaldehydes into δ keto esters and vinyl ethers at room temperature in a one-pot protocol in open-air (Scheme 1). Likewise, the organo-catalytic and nucleophilic behavior of DBU is well described.…”

“…To the best of our knowledge, there have been no developments on deformylative/dehalogenative difunctionalization in metal‐free conditions particularly by using DBU to synthesize δ‐oxo esters and vinyl ethers. In our previous work, we studied the organo‐catalytic behavior of DBU in 1,5 hydrogen atom transfer (HAT) in alkyl(E)‐3‐(2‐formyl3,4‐dihydronapthalen‐1‐yl)acrylate for the synthesis of highly fluorescent naphthalene probes [25] . Herein we have developed for the first time a facile and efficient catalyst‐/ metal‐ free DBU promoted deformylative/dehalogenative difunctionalizaton for the transformation of 1‐bromo‐3,4‐dihydronaphthalene‐2‐carbaldehydes into δ keto esters and vinyl ethers at room temperature in a one‐pot protocol in open‐air (Scheme 1).…”