Application of 1-(α-Aminobenzyl)-2-naphthols as Air-Stable Ligands for Pd-Catalyzed Mizoroki–Heck Coupling Reaction

Abstract

Air-stable, easily accessible Mannich bases, 1-(α-aminobenzyl)-2-naphthols, are used as ligands in palladium-catalyzed Mizoroki–Heck reaction on a variety of substrates. High turnover numbers are observed for both the reactions with aryl bromides and iodides, while aryl chlorides are inert.

GRAPHICAL ABSTRACT

Keywords:

• 1-(α-Aminobenzyl)-2-naphthols
• Mizoroki–Heck
• phosphine-free ligands

ACKNOWLEDGMENTS

We thank the Council of Scientific and Industrial Research (CSIR), New Delhi, for the award of a research fellowship to A. R. C. We are grateful to B. V. Kamath for his support and S. P. Sahoo of Sun Pharmaceutical Advanced Research Center for recording some of the NMR spectra.

Notes

Note. Compound 4 (Ar & Ar′ = Ph). All reactions run with K₂CO₃ (2.5 eq.) at 140 °C for 40 h, except entry 13.

^a With TBAB (0.25 eq.).

^b With NEt₃ (2.5 eq.).

^c TON–turn over number.