Department Chemie, Technische Universität Dresden, Bergstraße 66, 01069, Dresden, Germany.
Chemistry. 2016 Nov 14;22(47):16897-16911. doi: 10.1002/chem.201604002. Epub 2016 Oct 25.
We describe a regioselective synthesis of 4- or 5-substituted carbazoles by oxidative cyclisation of meta-oxygen-substituted N-phenylanilines. Using the regiodirecting effect of a pivaloyloxy group, we prepared 4-hydroxycarbazole, a precursor for the enantiospecific synthesis of the β-adrenoreceptor antagonists (-)-(S)-carazolol (5) and (-)-(S)-carvedilol (6). Regioselective palladium(II)-catalysed cyclisation of different diarylamines led to total synthesis of glycoborine (7) and the first total syntheses of the phytoalexin carbalexin A (8), glybomine A (9) and glybomine B (10). For glybomine B (10), a 5-hydroxycarbazole was converted into the corresponding triflate and utilized for introduction of a prenyl substituent.
我们描述了一种通过间位氧取代的 N- 苯基苯胺的氧化环化反应来合成 4- 或 5- 取代的咔唑的区域选择性合成方法。利用特戊酰氧基的区域导向效应，我们制备了 4- 羟基咔唑，这是手性选择性合成β-肾上腺素受体拮抗剂（- ）- （S ）-卡维地洛（5 ）和（- ）- （S ）-卡维洛尔（6 ）的前体。不同的二苯胺的区域选择性钯（II ）催化环化反应导致糖硼素（7 ）的全合成以及植物抗毒素 carbalexin A（8 ）、glybomine A（9 ）和 glybomine B（10 ）的首次全合成。对于 glybomine B（10 ），将 5- 羟基咔唑转化为相应的三氟甲磺酸酯，并用于引入一个 prenyl 取代基。
