628339-16-2Relevant academic research and scientific papers
Directed ortho-Metalation of O-Aryl N,N-Dialkylcarbamates: Methodology, Anionic ortho-Fries Rearrangement, and Lateral Metalation
Miah, M. A. Jalil,Sibi, Mukund P.,Chattopadhyay,Familoni, Oluwole B.,Snieckus, Victor
, p. 440 - 446 (2017/12/15)
The directed ortho-lithiation reactions of O-aryl N,N-dialkylcarbamates as well as O-1-naphthyl and O-2-naphthyl N,N-dialkylcarbamates with sec-butyllithium/tetramethylethylenediamine (sBuLi/TMEDA) followed by quenching with various electrophiles afford a range of polysubstituted aromatic compounds. If the solutions of the ortho-lithiated carbamates are warmed to room temperature without the addition of external electrophiles, salicylamide and 1- and 2-hydroxynaphthamide derivatives are formed through anionic ortho-Fries rearrangements. The relative stabilities and reactivities of different O-aryl N,N-dialkylcarbamates were investigated. The lateral metalation of 2-tolyl carbamates with lithium diisopropylamide (LDA) provides a route to benzo[b]furan-2(3H)-ones. Previously reported results are used in a comparison of seven O-based directed metalation groups in reactions with several electrophiles. The described methodology is useful for the preparation of 1,2,3-substituted aromatic compounds.
Synthesis of regioselectively functionalized benzo[b]thiophenes by combined ortho-lithiation-halocyclization strategies
Sanz, Roberto,Guilarte, Veronica,Hernando, Elsa,Sanjuan, Ana M.
supporting information; experimental part, p. 7443 - 7446 (2011/02/21)
An efficient synthesis of 3-halo-7-oxygen-functionalized benzo[b]thiophenes bearing different substituents at C-2 has been developed from N,N-diethyl O-3-halophenylcarbamates. The key steps are an ortho-lithiation reaction, which gives rise to 3-halo-2-su
Application of directed metalation in synthesis. Part 6: A novel anionic rearrangement under directed metalation conditions leading to heteroannulation
Pradhan, Tarun Kanti,Mukherjee, Chandrani,Kamila, Sukanta,De, Asish
, p. 5215 - 5224 (2007/10/03)
A short and efficient synthesis of condensed 1,4-oxathiin-2-ones from easily available phenols is described. The key step in this synthesis is a hitherto unreported anionic rearrangement under directed metalation conditions. The rearrangement occurs after
Application of directed metalation in synthesis. Part 5:1,2 Synthesis of condensed sulfur-oxygen heterocycle via novel anionic rearrangement-cyclisation
Mukherjee, Chandrani,Kamila, Sukanta,De, Asish
, p. 1474 - 1478 (2007/10/03)
Introduction of the methyl sulfanyl function in the ortho-position to O-carbamate functionality under standard directed metalation condition was followed by side-chain deprotonation with sec-butyl lithium at -78 °C. Upon warming to room temperature, the d
