Synthesis of stereodefined fused δ-hydroxy-γ-lactones from dealkylative cyclization of epoxy-diesters
摘要:
A dealkylative lactonization of stereodefined aryl-substituted epoxides allows the preparation of densely functionalized fused delta-hydroxy-gamma-lactones having three consecutive stereochemically defined stereocenters. (C) 2011 Elsevier Ltd. All rights reserved.
Pd-catalyzed intramolecular addition of active methylene compounds to alkynes, followed by subsequent cross-coupling with (hetero)aryl bromides and chlorides. The reaction proceeds under mild conditions, providing excellent functional group tolerance, including unprotected OH, NH2 groups, enolizable ketones, or a variety of heterocycles. Mechanistic studies point towards a catalyticcycle involving oxidative
An Efficient and General Microwave-Assisted Copper-Catalyzed Conia-Ene Reaction of Terminal and Internal Alkynes Tethered to a Wide Variety of Carbonucleophiles
作者:Sonia Montel、Didier Bouyssi、Geneviève Balme
DOI:10.1002/adsc.201000351
日期:2010.9.10
This paper describes a highly efficient, microwave‐assisted, Conia‐ene reaction of alkynes bearing a stabilizing carbon nucleophile. The reaction, catalyzed by a commercially available copper catalyst, proceeds under neutral conditions and is generally applicable even to less reactive nucleophiles such as malonate, cyanoacetate, and sulfonylacetate derivatives. This copper‐mediated cycloisomerization
A dealkylative lactonization of stereodefined aryl-substituted epoxides allows the preparation of densely functionalized fused delta-hydroxy-gamma-lactones having three consecutive stereochemically defined stereocenters. (C) 2011 Elsevier Ltd. All rights reserved.