Palladium-Catalyzed α-Arylation of Esters and Amides under More Neutral Conditions
作者:Takuo Hama、Xiaoxiang Liu、Darcy A. Culkin、John F. Hartwig
DOI:10.1021/ja036792p
日期:2003.9.1
aryl halides with alkalimetal enolates are reported. The first procedure rests upon the development of catalysts bearing the hindered pentaphenylferrocenyl di-tert-butylphosphine (Q-phos) and the highly reactive dimeric Pd(I) complex P(t-Bu)3]PdBr}2. By this procedure, zinc enolates prepared from α-bromo esters and amides react with aryl halides to form α-aryl esters and amides in high yields under
Palladium-Catalyzed Arylation of Trimethylsilyl Enolates of Esters and Imides. High Functional Group Tolerance and Stereoselective Synthesis of α-Aryl Carboxylic Acid Derivatives
作者:Xiaoxiang Liu、John F. Hartwig
DOI:10.1021/ja031544e
日期:2004.4.28
palladium-catalyzed arylation of trimethylsilyl enolates of esters and imides is reported. In the presence of ZnF2 or Zn(O-t-Bu)2 as an additive, the trimethylsilyl enolates of esters, including those bearing α-alkoxy derivatives, underwent arylation in high yield with high functional group tolerance. This arylation chemistry was extended to ester derivatives bearing chiral auxiliaries to form new tertiary stereocenters
JACKSON W. R.; RAE I. D.; WONG M. G., AUSTRAL. J. CHEM., 39,(1986) N 2, 303-315
作者:JACKSON W. R.、 RAE I. D.、 WONG M. G.
DOI:——
日期:——
US5468888A
申请人:——
公开号:US5468888A
公开(公告)日:1995-11-21
Palladium-Catalyzed α-Arylation of Zinc Enolates of Esters: Reaction Conditions and Substrate Scope
作者:Takuo Hama、Shaozhong Ge、John F. Hartwig
DOI:10.1021/jo401476f
日期:2013.9.6
The intermolecular α-arylation of esters by palladium-catalyzed coupling of aryl bromides with zinc enolates of esters is reported. Reactions of three different types of zinc enolates have been developed. α-Arylation of esters occurs in high yields with isolated Reformatsky reagents, with Reformatsky reagents generated from α-bromo esters and activated zinc, and with zinc enolates generated by quenching
报道了通过芳基溴化物与酯的烯醇锌的钯催化偶联实现酯的分子间α-芳基化。已经开发出三种不同类型的烯醇锌的反应。使用分离的 Reformatsky 试剂、使用由 α-溴代酯和活化锌生成的 Reformatsky 试剂以及使用氯化锌猝灭酯的碱金属烯醇化物生成的锌烯醇化物,可以高产率进行酯的 α-芳基化。使用烯醇锌代替碱金属烯醇化物大大扩展了酯的芳基化范围。该反应在室温或 70 °C 下与含有氰基、硝基、酯、酮、氟、烯醇化氢、羟基或氨基官能团的溴代芳烃以及与溴代吡啶发生。酯的范围包括无环乙酸酯、丙酸酯和异丁酸酯、α-烷氧基酯和内酯。使用带有受阻五苯基二茂铁基二叔丁基膦(Q-phos)或高反应性二聚Pd(I)络合物[P( t -Bu) 3 ]PdBr} 2 的催化剂进行酯的烯醇锌的芳基化。