Highly Regioselective Fluorination and Iodination of Alkynyl Enolates
摘要:
A simple yet efficient approach to various functionalized quaternary alpha-alkynyl alpha-fluoro esters and gamma-iodoallenoates from readily available allenoates through an alkynyl enolate intermediate generated by LDA is presented. Reaction of this alkynyl enolate with NFSI gives the alpha-product (alpha-alkynyl-alpha-fluoro ester), whereas the reaction of the silyl ether of alkynyl enolate with I-2 gives solely the gamma-product (iodoallenoate).
Michael Addition of Allenoates to Electron-Deficient Olefins: Facile Synthesis of 2-Alkynyl-Substituted Glutaric Acid Derivatives
作者:Le-Ping Liu、Bo Xu、Gerald B. Hammond
DOI:10.1021/ol801411b
日期:2008.9.1
A Michaeladdition of allenoates to electron-deficientolefins was mediated efficiently by a catalytic amount of commercial tetra-n-butylammonium fluoride (TBAF) under mild conditions. And 2-alkynyl substituted glutaric acid derivatives, which may be potential building blocks in organic synthesis, were obtained in good to excellent yields from these reactions. The mechanism for the Michael addition