本发明公开了一种 C 2‑对称性手性芳基碘催化剂的合成方法,属于有机化学技术领域。该方法是以廉价的3,5‑二甲氧基溴苯作为起始原料,通过与一系列芳基硼酸发生经典的Suzuki‑Miyaura偶联得到中间体3,5‑二甲氧基联苯,随即在三溴化硼作用下脱甲基保护基得到中间体3,5‑二羟基联苯;接下来,经过芳香族碘代,Mitsunobu反应引入手性源得到手性芳基碘酯类衍生物;将手性芳基碘酯类衍生物水解后,通过酰氯化与二级胺(二环己基胺)缩合得到目标手性芳基碘催化剂,总产率高达13.3%。
本发明公开了一种 C 2‑对称性手性芳基碘催化剂的合成方法,属于有机化学技术领域。该方法是以廉价的3,5‑二甲氧基溴苯作为起始原料,通过与一系列芳基硼酸发生经典的Suzuki‑Miyaura偶联得到中间体3,5‑二甲氧基联苯,随即在三溴化硼作用下脱甲基保护基得到中间体3,5‑二羟基联苯;接下来,经过芳香族碘代,Mitsunobu反应引入手性源得到手性芳基碘酯类衍生物;将手性芳基碘酯类衍生物水解后,通过酰氯化与二级胺(二环己基胺)缩合得到目标手性芳基碘催化剂,总产率高达13.3%。
ortho-Arylation of ortho-substituted benzoic acids is a challenging process due to the tendency of the reaction products toward Pd-catalyzed protodecarboxylation. A simple method for preventing decarboxylation in sterically hindered benzoic acids is reported. The method described represents a reliable and broadly applicable entry to 2-aryl-6-substituted benzoic acids.
Carboxylic Acids as Traceless Directing Groups for Formal meta-Selective Direct Arylation
作者:Josep Cornella、Marika Righi、Igor Larrosa
DOI:10.1002/anie.201103720
日期:2011.9.26
Without a trace: The first meta‐selective direct CH arylation that uses iodoarenes as coupling partners is reported (see scheme, EWG=electron‐withdrawing group). This process utilizes carboxylicacid units as temporary directinggroups that are cleaved during the reaction, leaving no trace in the resulting biaryl products.