Completely Regioselective Direct C–H Functionalization of Benzo[b]thiophenes Using a Simple Heterogeneous Catalyst
摘要:
The first completely selective C3 C-H arylation of benzo[b]thiophenes is reported, demonstrating previously unexploited reactivity of palladium. Benzo[b]thiophenes are coupled with readily available aryl chlorides using a ligand-free, dual catalytic system of heterogeneous Pd/C and CuCl. The reaction is operationally simple and insensitive to air and moisture, and it provides valuable products with complete selectivity. Significant investigations into the nature of the active catalytic species and mechanistic considerations are discussed.
Palladium-catalysed cross-coupling of 2,3-dibromobenzo[b]thiophene with phenylboronic acids bearing two ortho substi-tuents have been developed and used for the synthesis of sterically hindered 2,3-diarylbenzo[b]thiophenes.
The Interrupted Pummerer Reaction in a Sulfoxide‐Catalyzed Oxidative Coupling of 2‐Naphthols
作者:Zhen He、Alexander P. Pulis、David J. Procter
DOI:10.1002/anie.201903492
日期:2019.6.3
A benzothiopheneS‐oxide catalyst, generated in situ by sulfur oxidation with H2O2, mediates the oxidative coupling of 2‐naphthols. Key to the catalytic process is the capture and inversion of reactivity of a 2‐naphthol partner, using an interrupted Pummerer reaction of an unusualbenzothiopheneS‐oxide, followed by subsequent coupling with a second partner. The new catalytic manifold has been showcased
通过H 2 O 2硫氧化原位生成的苯并噻吩S-氧化物催化剂介导2-萘酚的氧化偶联。催化过程的关键是使用不寻常的苯并噻吩S-氧化物中断的Pummerer反应,然后与第二个配偶偶合,捕获和转化2-萘酚配偶的反应性。新的催化歧管已在生物活性天然产物(±)-尼莫酮和(±)-异麦酮的合成中得到展示。尽管Pummerer反应被广泛使用,但它们在催化中的应用却很少,我们的方法代表了一种新的无金属C-C键形成的催化流形。
Completely Regioselective Direct C–H Functionalization of Benzo[<i>b</i>]thiophenes Using a Simple Heterogeneous Catalyst
作者:Dan-Tam D. Tang、Karl D. Collins、Frank Glorius
DOI:10.1021/ja403130g
日期:2013.5.22
The first completely selective C3 C-H arylation of benzo[b]thiophenes is reported, demonstrating previously unexploited reactivity of palladium. Benzo[b]thiophenes are coupled with readily available aryl chlorides using a ligand-free, dual catalytic system of heterogeneous Pd/C and CuCl. The reaction is operationally simple and insensitive to air and moisture, and it provides valuable products with complete selectivity. Significant investigations into the nature of the active catalytic species and mechanistic considerations are discussed.