Green One-Pot Synthesis of 2H-Pyrans Under Solvent-Free Conditions Catalyzed by Ethylenediammonium Diacetate
作者:Martín J. Riveira、Mirta P. Mischne
DOI:10.1080/00397911.2011.594975
日期:2013.1
Abstract Ethylenediammonium diacetate readily catalyzes the Knoevenagel-type condensation between 1,3-dicarbonyl substrates and α,β-unsaturated aldehydes at room temperature undersolvent-freeconditions. This rapid, efficient, and convenient one-pot approach to the synthesis of 2H-pyrans stands as a significant advance over previously reported protocols. This environmentally friendly methodology has
Brønstedacidscatalyze the addition of enolizable β-diketones, β-ketoesters, and vinylogous amides to α,β-unsaturated aldehydes to lead to substituted chromenones, pyranones, and tetrahydroquinolinones in good yields under mild reaction conditions via a formal [3 + 3] cycloaddition.
Brønstedacidscatalyze the addition of enolizable β-keto esters to α,β-unsaturated aldehydes leading to substituted 2H-pyrans in good yields under mild conditions via a formal [3+3] cycloaddition.
Microwave-Assisted Solvent and Catalyst Free Synthesis of 2H-Pyrans
作者:Naushad Edayadulla、Yong Rok Lee
DOI:10.5012/bkcs.2013.34.10.2963
日期:2013.10.20
This paper describes a simple and efficient method involving domino Knovenegal/$6\pi}$ electrocyclization for the preparation of a variety of 2H-pyrans using microwave irradiation under solvent- and catalyst-free conditions. This method offers the advantages of a green approach, high yields, and short reaction times. Sixteen compounds (9a-p) were obtained in good to excellent yields using the procedure.