Relay Redox and Lewis Acid Catalysis in the Titanocene- Catalyzed Multicomponent Assembly of 1,5-Enynes
作者:Antonio J. Lepore、David M. Pinkerton、Brandon L. Ashfeld
DOI:10.1002/adsc.201300359
日期:2013.5.17
Herein we describe a direct, multicomponentassembly of 1,5‐enynes. The titanocene‐catalyzed coupling of an aryl aldehyde, iodoalkyne, and allylsilane enables the convergent and rapid synthesis of this versatile architectural motif in good to excellent yields.
Propargylic alcohols undergo smooth deoxygenative allylation with allylsilanes in the presence of a solution of 10 mol % of copper(II) tetrafluoroborate in acetonitrile to afford the corresponding 1,5-enynes in good to high yields under mild and neutral conditions. Scandium triflate is also found to catalyze efficiently the nucleophilic substitution of propargylic alcohols with allylsilanes. (c) 2007 Elsevier Ltd. All rights reserved.
Zinc-mediated Allylation of Aryl 2-Propynyl Acetates: A Facile Synthesis of 1,5-Enynes
作者:J. S. Yadav、B. V. Subba Reddy、D. Chandrakanth、B. Prashant
DOI:10.1246/cl.2008.954
日期:2008.9.5
Aryl 2-propynyl acetates undergo smooth allylation with allylzinc bromide (generated in situ from allyl bromide and zinc metal) in THF at room temperature under mild conditions to furnish the corresponding 1,5-enynes in good to excellent yields and with high selectivity. Indium metal is also found to accomplish the nucleophilic substitution of aryl 2-propynylic acetates with allyl bromide.