Parallel Synthesis of a Desketoraloxifene Analogue Library via Iodocyclization/Palladium-Catalyzed Coupling
摘要:
For a future structure-activity relationship (SAR) study, a library of desketoraloxifene analogues has been prepared by parallel synthesis using iodocyclization and subsequent palladium-catalyzed coupling reactions. Points of desketoraloxifene diversification involve the two phenolic hydroxyl groups and the aliphatic amine side chain. This approach affords oxygen bearing 3-iodobenzo[b]thiophenes 4 in excellent yields, which are easily further elaborated using a two-step approach involving Suzuki-Miyaura and Mitsunobu coupling reactions to give multimethoxy-substituted desketoraloxifene analogues 6. Various hydroxyl-substituted desketoraloxifene analogues 7 were subsequently generated by demethylation with BBr(3).
A new approach to desketoraloxifene analogs from oxygen-bearing 3-iodobenzo[b]thiophenes prepared via iodocyclization
作者:Chul-Hee Cho、Dai-Il Jung、Richard C. Larock
DOI:10.1016/j.tetlet.2010.09.137
日期:2010.12
A formal total synthesis of the benzothiophene selective estrogen receptor modulator (SERM) desketoraloxifene and analogs has been accomplished from alkynes bearing electron-rich aromatic rings by electrophilic cyclization using I2. This approach affords oxygen-bearing 3-iodobenzo[b]thiophenes in excellent yields, which are easily further elaborated using a two-step approach involving Suzuki–Miyaura
苯并噻吩选择性雌激素受体调节剂 (SERM) 去酮洛昔芬和类似物的正式全合成已通过使用 I 2 的亲电环化从带有富电子芳环的炔烃完成。这种方法以极好的收率提供了含氧的 3-碘苯并 [ b ] 噻吩,使用涉及 Suzuki-Miyaura 和 Mitsunobu 偶联反应的两步方法可以很容易地进一步阐述。
Synthesis of a 3-(α-Styryl)benzo[<i>b</i>]-thiophene Library via Bromocyclization of Alkynes and Palladium-Catalyzed Tosylhydrazones Cross-Couplings: Evaluation as Antitubulin Agents
efficiently synthesized by applying a synthetic sequence that allowed introduction of various substituents on aromatic A, B, and C-rings. The strategy developed involves the synthesis of 3-bromobenzo[b]thiophene derivatives through a bromocyclization step of methylthio-containing alkynes using N-methylpyrrolidin-2-one hydrotribromide reagent (MPHT). Further coupling of 3-bromobenzothiophenes under palladium-catalysis
通过应用允许在芳族A,B和C-上引入各种取代基的合成序列,有效合成了具有高水平分子多样性的功能化3-(α-苯乙烯基)-苯并[ b ]噻吩文库戒指。所开发的策略涉及通过使用N-甲基吡咯烷基-2-酮氢三溴化试剂(MPHT)通过含甲硫基炔烃的溴环化步骤合成3-溴苯并[ b ]噻吩衍生物。钯催化下的3-溴苯并噻吩与N-甲苯磺酰hydr的进一步偶联有效地提供了2-芳基-3-(α-苯乙烯基)苯并[ b噻吩衍生物。研究了目标化合物的抗增殖特性。其中,化合物5m对HCT-116细胞系表现出亚微摩尔的细胞毒活性,并在微摩尔水平上可与CA-4相比抑制微管蛋白的聚合。
Synthesis of 2‐Substituted Benzothio(seleno)phenes and Indoles
<i>via</i>
Ag‐Catalyzed Cyclization/Demethylation of 2‐Alkynylthio(seleno)anisoles and 2‐Alkynyldimethylanilines
Herein, we have successfully developed an efficient protocol for the construction of benzothio(seleno)phenes and indoles through an Ag‐mediated cyclization/demethylation process. Various 2‐substituted benzothio(seleno)phenes and indoles were obtained in good to excellent yields under mild reaction conditions with low catalyst loading. A conceivable reaction mechanism was proposed and supported by an
Cascade Radical Annulation of 2-Alkynylthio(seleno)anisoles with Acetone or Acetonitrile: Synthesis of 3-Acetomethyl- or Cyanomethyl-Substituted Benzothio(seleno)phenes
for the direct preparation of 3-aceto(cyano)methyl-substituted benzothio(seleno)phenes has been achieved throughC(sp3)–H bondactivation of easily available acetone or acetonitrile and cascade radical cyclization reaction. In this cascade radical cyclization reaction, C(sp2)–C(sp3) and C(sp2)–S bonds, as well as benzenethio(seleno)phene skeletons, can be built along with the cleavage of the C(sp3)–S