一种合成苯基硼酸频哪醇酯的新方法

Synthesis of Phenylboronate Pinacol Ester

工业上多采用将苯基溴代物金属化后再经过硼化和酯化反应合成苯基硼酸频哪醇酯,但该方法具有反应条件苛刻、官能团兼容性差、收率较低等缺点。研究了以苯基氯代物为原料,在Pd催化体系下,以B2（pin）2为硼试剂,在室温下合成其硼酸酯的新方法。研究表明,在0.5 mol%Xphos-Pd-G2和0.25 mol%Xphos催化体系下,以B2（pin）2为硼试剂、K3PO4·7H2O为碱、Et OH为溶剂,在室温下反应1 h,含不同取代基的苯基硼酸频哪醇酯收率均在92%以上。该方法具有原料廉价易得、官能团兼容性好、条件温和、操作简便、反应高效、适合大量制备等优点。

The industrial process for the preparation of phenylboronate pinacol ester is metallization of phenyl chlorides followed by boronation and esterification.However,the process has some disadvantages,such as harsh reaction conditions,poor compatibility of functional groups and low yield.In this work,a new approach to phenylboronate pinacol ester from phenyl chloride at room temperature,catalyzed by Pd and B2（ pin）2 using as boron reagent was investigated. Under the optimized reaction conditions,0. 5 mol%Xphos-Pd-G2,0. 25 mol% Xphos,B2（ pin）2 as boron reagent,K3PO4·7 H2O as base,the borylation of phenyl chlorides containing different substituents at room temperature for 1 h in EtOH afforded corresponding boronate pinacol ester with more than 92%yield.The approach has the advantages of cheap and available material,good compatibility of functional groups,mild conditions,simple operation,high efficiency and suitable for a large scale preparation.