Potent pincer-zinc catalyzed homogeneous α-alkylation and Friedländer quinoline synthesis reaction of secondary alcohols/ketones with primary alcohols.
Debashis JanaSima RoySrijita NaskarSupriyo HalderGopal KanrarKausikisankar PramanikPublished in: Organic & biomolecular chemistry (2024)
Herein, we describe an air- and moisture-stable, homogeneous zinc catalyst stabilised using an electron deficient N^N^N pincer-type ligand. This ternary, penta-coordinated neutral molecular catalyst [Zn(N^N^N)Cl 2 ] selectively produces α-alkylated ketone derivatives (14 examples) through a one-pot acceptorless dehydrogenative coupling (ADC) reaction between secondary and primary alcohols using the borrowing hydrogen (BH) approach in good to excellent isolated yields (up to 93%). It is worth noting that this catalyst also provides an eco-friendly route for the synthesis of quinoline derivatives (30 examples) using 2-aminobenzyl alcohols as alkylating agents via successive dehydrogenative coupling and N-annulation reactions. This cost effective, easy to synthesize and environmentally benign catalyst shows excellent stability in catalytic cycles under open-air conditions, as evident from its high turnover number (∼10 4 ), and is activated by using a catalytic amount of base under milder conditions.
Keyphrases
- room temperature
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- reduced graphene oxide
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- carbon dioxide
- metal organic framework
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- structure activity relationship
- body composition
- single molecule