Efficient synthesis of α-aryl esters by room-temperature palladium-catalyzed coupling of aryl halides with ester enolates
Efficient synthesis of α-aryl esters by room-temperature palladium-catalyzed coupling of aryl halides with ester enolates
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DOI：
10.1021/ja027643u
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发表时间：
2002-10-23
影响因子：
15
通讯作者：
Hartwig, JF
中科院分区：
文献类型：
--
作者：
Jorgensen, M;Lee, S;Hartwig, JF
催化量的Pd（dba）（2）与卡宾前体NAr-双（2，6-二异丙基苯基）4，5-二氢咪唑鎓（1）或P（t-Bu）（3）配位，在室温下介导芳基卤化物和酯烯醇化物的偶联，高产率地生成α-芳基酯。该反应对芳基卤上的官能团和取代模式具有高度耐受性。以LiNCy 2为碱，P（t-Bu）（3）为配体，改进了乙酸叔丁酯的选择性单芳基化反应和α，α-二取代酯的高效芳基化反应.此外，在Pd（dba）（2）和受阻饱和杂环卡宾配体前体的存在下，由丙酸叔丁酯和芳基溴以高产率制备了叔丁酯，例如Na 2CO 3 en和氟比洛芬的那些。
A catalytic amount of Pd(dba)(2) ligated by either carbene precursor NAr-bis(2,6-diisopropylphenyl)4,5-dihydroimidazolium (1) or P(t-Bu)(3) mediated the coupling of aryl halides and ester enolates to produce alpha-aryl esters in high yields at room temperature. The reaction was highly tolerant of functionalities and substitution patterns on the aryl halide. Improved protocols for the selective monoarylation of tert-butyl acetate and the efficient arylation of alpha,alpha-disubstituted esters were developed with LiNCy2 as base and P(t-Bu)(3) as ligand. In addition, tert-butyl esters, such as those of Naproxen and Flurbiprofen, were prepared from tert-butyl propionate and aryl bromides in high yields in the presence of Pd(dba)(2) and the hindered, saturated heterocyclic carbene ligand precursor.