A visible-light-engaged 2-fold site-selective alkylation of indole derivatives with aliphatic ethers or alcohols has been accomplished for easy access to symmetric 3,3′-bisindolylmethane derivatives. The experimental data suggest a sequential photoredoxcatalysis induced radical addition and proton-mediated Friedel–Crafts alkylation mechanism.
Directed <i>o</i><i>rtho </i>Metalation Approach to C-7-Substituted Indoles. Suzuki−Miyaura Cross Coupling and the Synthesis of Pyrrolophenanthridone Alkaloids
作者:Christian G. Hartung、Anja Fecher、Brian Chapell、Victor Snieckus
DOI:10.1021/ol0344772
日期:2003.5.1
overall yields. In combination with the Suzuki-Miyaura protocol, C-7 aryl (heteroaryl)-substituted indoles 14 and 16 are obtained, including hippadine and pratosine, members of the pyrrolophenanthridone alkaloid family.
economical and stereoselective synthesis of tetrasubstituted α,β‐unsaturated amides was achieved by a Cp*CoIII‐catalyzed C−H alkenylation/directing group migration sequence. A carbamoyl directing group, which is typically removed after C−H functionalization, worked as an internal acylating agent and migrated onto the alkene moiety of the product. The directing group migration was realized with the
通过Cp * Co III催化的CH烯基化/方向基团迁移序列,实现了高度原子经济和立体选择性的四取代α,β-不饱和酰胺的合成。通常在CH官能化后被除去的氨基甲酰基导向基团作为内部酰化剂起作用,并迁移到产物的烯烃部分上。使用Cp * Co III催化剂可实现导向基团的迁移,而相关的Cp * Rh III催化剂则不会促进迁移过程。将产物进一步转化为两种类型的三环化合物,其中一种具有荧光性质。
Rhodium-Catalyzed Direct Addition of Indoles to<i>N</i>-Sulfonylaldimines
作者:Bing Zhou、Yaxi Yang、Sui Lin、Yuanchao Li
DOI:10.1002/adsc.201200909
日期:2013.1.25
The rhodium-catalyzedaddition of indole CH bonds to a range of aryl- and alkyl-N-sulfonylaldimines is reported. The reaction proceeds with high functional group compatibility and provides easy and rapid access to a wide variety of 2-indolylmethanamine derivatives under mild reaction conditions.
A mechanism‐navigated enantioselective alkylation of an indole C2 C–Hbond with an internal alkene was developed. Under the inharmonious ligand‐to‐metal catalyst ratio, a moderate enantiomeric ratio (er) was achieved with our original ligand. We propose that chain‐walking and bondformation are mechanistically independent, and suggest that hydridoiridium does not play a role in the chain‐walking process