Molecular iodine-catalyzed C3-alkylation of 4-hydroxycoumarins with secondary benzyl alcohols
摘要:
A highly efficient method for the C-C bond formation via molecular iodine-catalyzed C3-alkylation reaction of 4-hydroxycoumarins with benzylic, benzhydrylic, allylic, and propargyl alcohols at 50 degrees C in MeNO2 is described. The 3-alkylated-4-hydroxycoumarins were obtained in good yields (up to 97%). By applying this reaction as the key step, a multi-substituted pyranocoumarin can easily be synthesized in a one-pot procedure. The advantages of this method are broad scope, mild conditions, and easy handling since water is the only side product. (C) 2009 Elsevier Ltd. All rights reserved.
Highly Stereoselective Synthesis of Natural-Product-Like Hybrids by an Organocatalytic/Multicomponent Reaction Sequence
作者:Radell Echemendía、Alexander F. de La Torre、Julia L. Monteiro、Michel Pila、Arlene G. Corrêa、Bernhard Westermann、Daniel G. Rivera、Márcio W. Paixão
DOI:10.1002/anie.201412074
日期:2015.6.22
In an endeavor to provide an efficient route to natural product hybrids, described herein is an efficient, highly stereoselective, one‐pot process comprising an organocatalytic conjugate addition of 1,3‐dicarbonyls to α,β‐unsaturated aldehydes followed by an intramolecular isocyanide‐based multicomponent reaction. This approach enables the rapid assembly of complex natural product hybrids including