Redox-Neutral Rhodium(III)-Catalyzed Chemospecific and Regiospecific [4+1] Annulation between Indoles and Alkenes for the Synthesis of Functionalized Imidazo[1,5-<i>a</i>]indoles
unit, a redox-neutral rhodium(III)-catalyzed chemo- and regiospecific [4+1] annulation between indoles and alkenes for the synthesis of functionalized imidazo[1,5-a]indoles has been achieved. Internal alkenes employed here can fulfill an unusual [4+1] annulation rather than normal [4+2] annulation/C–Halkenylation. This method is characterized by excellent chemo- and regioselectivity, broad substrate scope
利用嵌入氧化功能/离去基团的内部烯烃作为稀有和非常规的单碳单元,氧化还原中性铑(III)催化的吲哚和烯烃之间的化学和区域特异性[4 + 1]环化,用于合成功能化咪唑并[1,5- a ]吲哚已经实现。这里使用的内部烯烃可以实现不寻常的 [4+1] 环化,而不是正常的 [4+2] 环化/C-H 烯基化。该方法的特点是优异的化学和区域选择性、广泛的底物范围、良好的官能团耐受性、良好的收率和氧化还原中性条件。
Rhodium(III)-Catalyzed C–H Alkenylation/Directing Group Migration for the Regio- and Stereoselective Synthesis of Tetrasubstituted Alkenes
indoles and alkynes for the assembly of tetrasubstituted alkenes is reported. The carbamoyl directing group migrates to the carbon of the alkene moiety of the products through rare Rh-catalyzed C–N bond cleavage after the C–H alkenylation step and thus acts as an internal amidation reagent. This protocol shows broad substrate scope, excellent regio/stereoselectivity, and good to excellent yields.
Rh(<scp>iii</scp>)-Catalyzed C(sp<sup>2</sup>)–H functionalization/cyclization cascade of <i>N</i>-carboxamide indole and iodonium reagents for access to indoloquinazolinone derivatives
作者:Zhi-Peng Han、Meng-Meng Xu、Rui-Ying Zhang、Xiao-Ping Xu、Shun-Jun Ji
DOI:10.1039/d1gc01820e
日期:——
A rhodium-catalyzed synthesis of indoloquinazolinone from a readily available hypervalent iodonium reagent and N-carboxamide indole was developed. The protocol features broad functional group tolerance, mild conditions, and excellent yields. The target products were obtained simply by filtration, without tedious column chromatography. Notably, the noble metal catalyst system can be recycled effectively
Here we report an aerobic Pd(0) catalyzed C2–H functionalization of indoles and pyrroles with tethered N-methoxylamide as the directing group. A Pd(0)-initiated mechanism overcomes the directing or poisoning effect from a wide range of heterocycles including pyridine, pyrimidine, and thiazole. The imidazo[1,5-a]indole products are transformed to bioactive analogs after one-step manipulations, demonstrating
在这里我们报告了一个有氧的Pd(0)催化的吲哚和吡咯的C2-H官能化,其中N-甲氧基酰胺为连接基团。Pd(0)引发的机制克服了包括吡啶,嘧啶和噻唑在内的各种杂环的直接或中毒作用。一步操作后,咪唑并[1,5- a ]吲哚产物转化为生物活性类似物,证明了该反应在药物发现中的潜在效用。
The ruthenium(<scp>ii</scp>)-catalyzed C–H olefination of indoles with alkynes: the facile construction of tetrasubstituted alkenes under aqueous conditions
An environmentally-friendly and facile protocol for the construction of tetrasubstituted alkenes has been established with Ru(ii)-catalyzed C–H bond functionalizations under mild conditions.