1394401-56-9Relevant academic research and scientific papers
Oxidative Cyclization of o-(1-Hydroxy-2-alkynyl)- N-tosylanilides for the Synthesis of 4-Quinolones
Ueda, Jun-Ichi,Enomoto, Yuuki,Seki, Mizuki,Konishi, Takuma,Ogasawara, Masamichi,Yoshida, Kazuhiro
, p. 6420 - 6428 (2020)
The treatment of easily accessible o-(1-hydroxy-2-alkynyl)-N-tosylanilides 1 with excess manganese(IV) oxide in the presence of substoichiometric tetrabutylammonium iodide (TBAI) in chloroform (or in the absence of TBAI in dimethylformamide, DMF) promoted a sequential oxidation/intramolecular hydroamination to give 4-quinolones 3 and/or (Z)-2-alkylidene-3-oxindoles (Z)-4 in good yields. Possibly, MnO2 played dual roles as an oxidant and as a Lewis acidic activator of intermediary ynones 2. The product distributions between 3 and (Z)-4 could be controlled by the choice of solvents.
One-pot relay catalysis: Divergent synthesis of furo[3,4-: B] indoles and cyclopenta [b] indoles from 3-(2-aminophenyl)-1,4-enynols
Manisha,Dhiman, Seema,Mathew, Jopaul,Ramasastry
, p. 5563 - 5568 (2016)
Described herein is an efficient divergent strategy for the synthesis of furo[3,4-b]indoles via a sequential Ag(i)/Bi(iii)/Pd(ii) catalysis and cyclopenta[b]indoles via a one-pot Ag(i)/Br?nsted acid relay catalysis from 3-(2-aminophenyl)-4-pentenyn-3-ols, accessible in three simple steps from 2-aminobenzaldehydes.
Cascade Skeletal Rearrangement of Gold Carbene Intermediates: Synthesis of Medium-Sized Pyrimidine-Fused Benzolactones
Hu, Xiaoping,Liu, Yuanhong,Wang, Ali,Xie, Xin
, p. 3769 - 3774 (2021)
A gold-catalyzed cyclization/cascade skeletal rearrangement of o-cyanophenylalkynones with 3-amino-benzo[d]-isoxazoles has been developed, which provides an approach for synthesizing medium-sized benzolactones. Based on the experimental results, we postul
Substituent-Guided Palladium-Ene Reaction for the Synthesis of Carbazoles and Cyclopenta[ b]indoles
Yadav, Sonu,Hazra, Raju,Singh, Animesh,Ramasastry
supporting information, (2019/05/07)
An efficient palladium-catalyzed intramolecular Trost-Oppolzer type Alder-ene strategy was developed for the synthesis of carbazoles and cyclopenta[b]indoles from easily accessible(3-allyl-1H-indol-2-yl)methyl acetates. This strategy was extended for the synthesis of naphthalenes and dibenzobenzofurans as well. In addition, a short synthesis of antibacterial and antifungal natural product glycozoline and its analogues was also achieved.
Substituent-Guided Palladium-Ene Reaction for the Synthesis of Carbazoles and Cyclopenta[b]indoles
Yadav, Sonu,Hazra, Raju,Singh, Animesh,Ramasastry
supporting information, p. 2983 - 2987 (2019/05/10)
An efficient palladium-catalyzed intramolecular Trost-Oppolzer type Alder-ene strategy was developed for the synthesis of carbazoles and cyclopenta[b]indoles from easily accessible(3-allyl-1H-indol-2-yl)methyl acetates. This strategy was extended for the synthesis of naphthalenes and dibenzobenzofurans as well. In addition, a short synthesis of antibacterial and antifungal natural product glycozoline and its analogues was also achieved.
Divergence in Ynone Reactivity: Atypical Cyclization by 3,4-Difunctionalization versus Rare Bis(cyclization)
Alcaide, Benito,Almendros, Pedro,Lázaro-Milla, Carlos,Delgado-Martínez, Patricia
, p. 8186 - 8194 (2018/06/15)
Functionalized ynones can be activated by Tf2C=CH2, which was generated in situ, to form zwitterionic species. These species were trapped in an intramolecular fashion by several nucleophiles to generate two major types of triflones in a divergent manner. Through fine-tuning of the reaction temperature, bis(triflyl)-6-membered- or (triflyl)-5-membered-fused-heterocycles were achieved in reasonable yields in a totally selective manner. In this way, bis(triflyl)flavones, bis(triflyl)thioflavones, bis(triflyl)selenoflavones, (triflyl)benzothienopyrans, (triflyl)benzoselenophenopyrans, (triflyl)vinyl aurones, and (triflyl)pyranoindoles were constructed. Conceivable mechanistic pathways were suggested on the basis of the isolation of several intermediates and the results from control experiments.
Transition-Metal-Free Decarboxylative Propargylic Substitution/Cyclization with either Azolium Enolates or Acyl Anions
Lu, Shenci,Ong, Jun-Yang,Poh, Si Bei,Tsang, Terence,Zhao, Yu
supporting information, p. 5714 - 5719 (2018/04/30)
Presented herein is an unprecedented transition-metal-free propargylic substitution reaction with either azolium enolates or acyl anions, which are generated from aldehydes under N-heterocyclic carbene catalysis. This new catalytic activation operates on readily available cyclic propargylic carbamates through decarboxylation, and generates reactive allene intermediates that can undergo divergent cyclization pathways to deliver skeletally diverse polycyclic compounds with high levels of efficiency and excellent enantioselectivities.
One-Pot Trimetallic Relay Catalysis: A Unified Approach for the Synthesis of β-Carbolines and Other [c]-Fused Pyridines
Dhiman, Seema,Mishra, Uttam K.,Ramasastry
supporting information, p. 7737 - 7741 (2016/07/07)
A divergent strategy is presented for the synthesis of 1,3-di- and 1,3,4-trisubstituted β-carbolines through an unprecedented one-pot triple-orthogonal-metal relay catalysis, and 1,3-disubstituted 4-hydroxy-β-carbolines through a one-pot bimetallic relay
Synthesis of polysubstituted cyclopenta[b]indoles via relay gold(i)/Bronsted acid catalysis
Dhiman, Seema,Ramasastry
, p. 557 - 560 (2015/01/09)
An efficient relay catalytic process involving Au(i)/Bronsted acid to access various polysubstituted cyclopentannulated indoles from easily accessible 1-(2-aminophenyl)prop-2-ynols and readily available 1,3-dicarbonyls has been developed. In an unprecedented event, the intermediate 2-indolylmethyl cations undergo the cation-Ene reaction with various 1,3-dicarbonyls followed by an intramolecular Friedel-Crafts-type reaction generating functionalized cyclopenta[b]indoles. This journal is
Silver acetate catalyzed hydroamination of 1-(2-(sulfonylamino)phenyl)prop- 2-yn-1-ols to (Z)-2-methylene-1-sulfonylindolin-3-ols
Susanti, Dewi,Koh, Fujiet,Kusuma, Jeffrey Antonius,Kothandaraman, Prasath,Chan, Philip Wai Hong
, p. 7166 - 7175 (2012/10/29)
A method to prepare (Z)-2-methylene-1-sulfonylindolin-3-ols efficiently that relies on silver acetate catalyzed hydroamination of 1-(2-(sulfonylamino) phenyl)prop-2-yn-1-ols is reported. The reactions proceed rapidly at room temperature with catalyst loadings as low as 1 mol % under conditions that did not require the exclusion of air or moisture. The utility of this N-heterocyclic ring-forming strategy as a synthetic tool that makes use of unsaturated alcohols was exemplified by the conversion of the (Z)-2-methylene-1- sulfonylindolin-3-ol to examples of other members of the indole family of compounds.
