Potassium <i>tert</i>-Butoxide Promoted Intramolecular Arylation via a Radical Pathway
作者:Daniela Sustac Roman、Yoko Takahashi、André B. Charette
DOI:10.1021/ol201160s
日期:2011.6.17
Potassium tert-butoxide mediated intramolecular cyclization of aryl ethers, amines, and amides was efficiently performed under microwave irradiation to provide the corresponding products in high regioisomeric ratios. The reaction proceeds via single-electron transfer to initiate the formation of an arylradical, followed by a kinetically favored 5-exo-trig and subsequent ring expansion.
Bis(dibenzylideneacetone)palladium(0)/<i>tert-</i>Butyl Nitrite- Catalyzed Cyclization of<i>o</i>-Alkynylanilines with<i>tert-</i>Butyl Nitrite: Synthesis and Applications of Indazole 2-Oxides
作者:Gopal Chandru Senadi、Ji-Qi Wang、Babasaheb Sopan Gore、Jeh-Jeng Wang
DOI:10.1002/adsc.201700456
日期:2017.8.17
An efficient method for the synthesis of 1‐benzyl/arylindazole 2‐oxides via a bis(dibenzylideneacetone)palladium(0) [Pd(dba)2]/tert‐butyl nitrite (TBN)‐catalyzed reaction of o‐alkynylaniline derivatives with TBN is reported. The overall transformation involves the formation of three new bonds via N‐nitrosation (N–NO), 5‐exo‐dig cyclization (C–N) and oxidation (C=O). The notable features are the mild
carbonylation reaction for the synthesis of N‐acetyl benzoxazinones has been achieved for the first time. To avoid the using of toxic and flammable CO gas, formic acid was utilized as the CO source here. This carbonylative process is conducted under mild reaction conditions with high reaction efficiency. A variety of the desired N‐acetyl benzoxazinone products were obtained in moderate to excellent yields
A new synthesis of indoles via intramolecular cyclization of ο-alkynyl N,N-dialkylanilines promoted by KOt-Bu/DMSO
作者:Yan-yan Chen、Jia-hua Chen、Niu-niu Zhang、Lin-miao Ye、Xue-Jing Zhang、Ming Yan
DOI:10.1016/j.tetlet.2014.12.002
日期:2015.1
2-Aryl indoles could be prepared in excellent yields via the intramolecular cyclization of o-alkynyl N,N-dialkylanilines. The reaction is efficiently promoted by the catalytic amount of KOr-Bu in DMSO at room temperature. A reaction mechanism involving alpha-aminoalkyl radical intermediates is suggested. (C) 2012 Elsevier Ltd. All rights reserved.
Alternating Iodonium-Mediated Reaction Cascades Giving Indole- And Quinoline-Containing Polycycles
作者:Rosliana Halim、Peter J. Scammells、Bernard L. Flynn
DOI:10.1021/ol800202u
日期:2008.5.1
A simple two-step convergent protocol gives direct access to synthetic intermediate A from ortho-iodoanilines. Intermediate A can be treated with NIS in CH(2)Cl(2) to induce novel iodonium mediated domino reaction cascade, which provides direct access to ring-fused indole compounds B. Simply by changing the reaction conditions, this protocol can be directed down an alternative domino reaction cascade to give various ring fused quinoline compounds C.