69737-65-1Relevant academic research and scientific papers
Electrochemical Reductive Smiles Rearrangement for C-N Bond Formation
Chang, Xihao,Zhang, Qinglin,Guo, Chang
supporting information, p. 10 - 13 (2019/01/04)
A conceptually new and synthetically valuable radical Smiles rearrangement reaction is reported under undivided electrolytic conditions. This protocol employs an entirely new strategy for the electrochemical radical Smiles rearrangement. Remarkably, an amidyl radical generated from the cleavage of the N-O bond under reductive electrolytic conditions plays a crucial role in this transformation. Various hydroxylamine derivatives bearing different substituents are suitable in this electrochemical transformation, furnishing the corresponding amides in up to 86% yield.
Formal Aniline Synthesis from Phenols through Deoxygenative N-Centered Radical Substitution
Lardy, Samuel W.,Luong, Kristine C.,Schmidt, Valerie A.
supporting information, p. 15267 - 15271 (2019/12/11)
Phenolic, lignin-derived substrates have emerged as desirable biorenewable chemical feedstocks for coupling reactions. A radical-mediated conversion of phenol derivatives to anilines is reported, using unfunctionalized hydroxamic acids as the N-centered radical source. The applicability of this triethyl phosphite mediated O-atom transfer approach, which tolerates a range of steric and electronic demands to naturally occurring phenols and lignin models, has been demonstrated in this work to access the corresponding aniline derivatives.
Efficient Aryl Migration from an Aryl Ether to a Carboxylic Acid Group To Form an Ester by Visible-Light Photoredox Catalysis
Wang, Shao-Feng,Cao, Xiao-Ping,Li, Yang
supporting information, p. 13809 - 13813 (2017/10/24)
We have developed a highly efficient aryl migration from an aryl ether to a carboxylic acid group through retro-Smiles rearrangement by visible-light photoredox catalysis at ambient temperature. Transition metals and a stoichiometric oxidant and base are avoided in the transformation. Inspired by the high efficiency of this transformation and the fundamental importance of C?O bond cleavage, we developed a novel approach to the C?O cleavage of a biaryl ether to form two phenolic compounds, as demonstrated by a one-pot, two-step gram-scale reaction under mild conditions. The aryl migration exhibits broad scope and can be applied to the synthesis of pharmaceutical compounds, such as guacetisal. Primary mechanistic studies indicate that the catalytic cycle occurs by a reductive quenching pathway.
Dibenzocyclooctene-, Dibenzochalcocine-, and Diarenochalconinediones
Hellwinkel, Dieter,Bohnet, Siegbert
, p. 1151 - 1174 (2007/10/02)
2,2'-Oxybis-, -thiobis-, and -methylenebisbenzoic esters 2a-c react with methyllithium in ether to give low yields of 5H-dibenzochalcocine-5,7(6H)-diones 6a, 7a, and dibenzocyclooctene-5,7(6H,12H)-dione (8), respectively.Very good yields of such heterocycles with oxygen (6a-h, 37), sulfur (7a-h, 38) and selenium (36) as key atom are obtained when diaryl ethers (21, 22, 25), -sulfides (27, 29, 30), and -selenides (33) that contain 2'-acetyl- (or -propionyl-) and 2-methoxycarbonyl groups are treated with sodium hydride in boiling toluene.Analogously are prepared the dibenzoxonine-11,13(6H,12H)diones 62a-c and 7H-benzonaphthothionine-7,9-(8H)-dione (65) which are expanded by one ring member.In the analogous reaction of a corresponding benzophenone derivative 35, spiro-3(2H),3'-dione (41) is formed in a tandem reaction. - Under phase transfer conditions the dibenzochalcocinediones 6, 7, 36 and also the corresponding nitrogen cycles 5 react to give mixtures of C- (42-45) and O-alkyl derivatives (46-49).Methyllithium and diisobutylaluminium hydride provide the carbinols 50-54.With bromine and SO2Cl2, respectively, the methylene group is mono- or dihalogenated to the products 56, 57; defined nitration was only possible for the oxacycle 6a.
