Access to Spirocyclized Oxindoles and Indolenines via Palladium-Catalyzed Cascade Reactions of Propargyl Carbonates with 2-Oxotryptamines and Tryptamines
作者:Antoinette E. Nibbs、Thomas D. Montgomery、Ye Zhu、Viresh H. Rawal
DOI:10.1021/acs.joc.5b00277
日期:2015.5.15
through a process wherein the first nucleophilic unit on the oxindole or indole reacts with an allenyl-palladium species, formed from oxidative addition of Pd(0) to propargyl carbonates, to generate a π-allyl palladium intermediate that then reacts further with the second nucleophilic component of the oxindole or indole. The cascade process forges two bonds en route to spirocyclized oxindole and indolenine
5‐(Cyano)dibenzothiophenium Triflate: A Sulfur‐Based Reagent for Electrophilic Cyanation and Cyanocyclizations
作者:Xiangdong Li、Christopher Golz、Manuel Alcarazo
DOI:10.1002/anie.201904557
日期:2019.7.8
and its reactivity as electrophilic cyanation reagent evaluated. The scalable preparation, easy handling and broad substrate scope of the electrophilic cyanation promoted by 9, which includes amines, thiols, silyl enol ethers, alkenes, electron rich (hetero)arenes and polyaromatic hydrocarbons, illustrate the synthetic potential of this reagent. Importantly, Lewis acid activation of the reagent is not
X-Ray Characterization of an Electron Donor-Acceptor Complex that Drives the Photochemical Alkylation of Indoles
作者:Sandeep R. Kandukuri、Ana Bahamonde、Indranil Chatterjee、Igor D. Jurberg、Eduardo C. Escudero-Adán、Paolo Melchiorre
DOI:10.1002/anie.201409529
日期:2015.1.26
A metal‐free, photochemical strategy for the direct alkylation of indoles was developed. The reaction, which occurs at ambient temperature, is driven by the photochemical activity of electrondonor–acceptor (EDA) complexes, generated upon association of substituted 1H‐indoles with electron‐accepting benzyl and phenacyl bromides. Significant mechanistic insights are provided by the X‐ray single‐crystal
Synthesis of Carbolines via Palladium/Carboxylic Acid Joint Catalysis
作者:Gianpiero Cera、Matteo Lanzi、Davide Balestri、Nicola Della Ca’、Raimondo Maggi、Franca Bigi、Max Malacria、Giovanni Maestri
DOI:10.1021/acs.orglett.8b01072
日期:2018.6.1
The combination of a Pd(0) complex with benzoic acid converts propargylic tryptamines to the corresponding tetrahydro-β-carbolines. The method uses unprotected indoles and affords the desired products with ample functional group tolerance. Detailed modeling studies reveal a close synergy between the organic and metal catalysts, which enables sequential alkyne isomerization, indole C–H activation, and
A study on the SN2-type ringopeningreactions of aziridines with indoles as nucleophiles is reported. Under gold(I) catalysis a great variety of tryptamine derivatives were prepared in good to excellent yields with complete stereocontrol when chiral aziridines were used. We demonstrated that cationic gold(I) catalysts are superior Lewis acids to the previously reported group 3, 12 and 13 metals in