A New Strategy for the Synthesis of Chiral β-Alkynyl Esters via Sequential Palladium and Copper Catalysis
作者:Barry M. Trost、Benjamin R. Taft、James T. Masters、Jean-Philip Lumb
DOI:10.1021/ja203171x
日期:2011.6.8
new strategy for the synthesis of chiral β-alkynyl esters which relies on sequential Pd and Cu catalysis is reported. Terminalalkynes bearing aryl, alkyl, and silyl groups can be employed without prior activation yielding a wide range of important chiral building blocks. The reaction sequence utilizes a robust Pd(II)-catalyzed hydroalkynylation of ynoates with terminalalkynes providing geometrically
4-Tributylstannyl,2-(5H)-furanone and pyrrolone have been prepared in good yields by addition of mixed stannylcuprate reagent on γ-amino and γ-hydroxy acetylenic esters. The use of these compounds as useful intermediates for the selective functionalization of these heterocyclic rings is discussed.
An Atom-Economic Synthesis of Nitrogen Heterocycles from Alkynes
作者:Barry M. Trost、Jean-Philip Lumb、Joseph M. Azzarelli
DOI:10.1021/ja110117g
日期:2011.2.2
A robust route to 2,4-disubstituted pyrrole heterocycles relying upon a cascade reaction is reported. The reaction benefits from operational simplicity: it is air and moisture tolerant and is performed at ambient temperature. Control over the reaction conditions provides ready access to isopyrroles, 2,3,4-trisubstituted pyrroles, and 3-substituted pyrollidin-2-ones.
3-(Tributylstannyl)allyl Alcohols: Useful Building Blocks for Solid-Phase Synthesis of Skipped Dienes and Trienes
作者:Miroslav Havránek、Dalimil Dvořák
DOI:10.1135/cccc20000434
日期:——
Repeated Stille coupling of 3-substituted 3-(tributylstannyl)allyl alcohols 2 on a solid support was used to synthesize a 21 × 21 library of skipped dienes and a 21 × 21 × 21 library of skipped trienes. Starting 3-(tributylstannyl)allyl alcohols were prepared by Pd-catalyzed hydrostannation of substituted prop-2-yn-1-ols, by hydroalumination by LiAlH4 followed with transmetallation to tin using tributyltin methoxide, or by substitution of chlorine in (Z)-6-chloro-3-(tributylstannyl)hex-2-en-1-ol with appropriate nucleophile. Synthesized libraries were tested for the activity to endorphin receptors, but with negative results.