182962-47-6Relevant articles and documents
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.
Lithiation of a silyl ether: Formation of an ortho-fries hydroxyketone
Lo, Hong-Jay,Lin, Chin-Yin,Tseng, Mei-Chun,Chein, Rong-Jie
, p. 9026 - 9029 (2014/09/17)
A hydroxy-directed alkylation of an N,N-diethylarylamide using CIPE-assisted α-silyl carbanions (CIPE=complex-induced proximity effect) has been developed using a simple reagent combination of LDA (lithium diisopropylamide) and chlorosilane. A study of the mechanism, and the application of the procedure to an anionic Snieckus-Fries rearrangement for a highly efficient synthesis of the potent phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, are reported.
Developing the Scope of O→C Aryl Migrations: Exploring Amide Substrates as Potential Precursors for Asymmetric Reactions
Ameen, Dana,Snape, Timothy J.
, p. 1925 - 1934 (2015/10/05)
A new and mild method for the production of diasteromerically enriched α-aryl carbonyl compounds has been achieved. Although only modest diastereoselectivies are observed, they demonstrate the potential of the method for further optimisation. It also appears that reactions that proceed through a five-membered spirocyclic transition state rearrange, whereas those proceeding through a six-membered transition state do not, but stop at the diaryl ether stage. A mild O→C aryl migration (Truce-Smiles rearrangement reaction) has been expanded to include amides as precursors, and it has been shown that the product ratios are dependent on the structure of the starting amides. Chiral auxiliaries have been incorporated in attempts to make the rearrangement asymmetric and modest diastereoselectivities were obtained.
