35954-01-9Relevant articles and documents
Ultrafast amidation of esters using lithium amides under aerobic ambient temperature conditions in sustainable solvents
Bole, Leonie J.,Fairley, Michael,García-Alvarez, Joaquín,Hevia, Eva,Kennedy, Alan R.,Main, Laura,Mulks, Florian F.,O'Hara, Charles T.
, p. 6500 - 6509 (2020/07/15)
Lithium amides constitute one of the most commonly used classes of reagents in synthetic chemistry. However, despite having many applications, their use is handicapped by the requirement of low temperatures, in order to control their reactivity, as well as the need for dry organic solvents and protective inert atmosphere protocols to prevent their fast decomposition. Advancing the development of air- and moisture-compatible polar organometallic chemistry, the chemoselective and ultrafast amidation of esters mediated by lithium amides is reported. Establishing a novel sustainable access to carboxamides, this has been accomplished via direct C-O bond cleavage of a range of esters using glycerol or 2-MeTHF as a solvent, in air. High yields and good selectivity are observed while operating at ambient temperature, without the need for transition-metal mediation, and the protocol extends to transamidation processes. Pre-coordination of the organic substrate to the reactive lithium amide as a key step in the amidation processes has been assessed, enabling the structural elucidation of the coordination adduct [{Li(NPh2)(OCPh(NMe2))}2] (8) when toluene is employed as a solvent. No evidence for formation of a complex of this type has been found when using donor THF as a solvent. Structural and spectroscopic insights into the constitution of selected lithium amides in 2-MeTHF are provided that support the involvement of small kinetically activated aggregates that can react rapidly with the organic substrates, favouring the C-O bond cleavage/C-N bond formation processes over competing hydrolysis/degradation of the lithium amides by moisture or air.
Selective introducing of aryl and amino groups: Reaction of benzanthrone and organometallic reagents
Umeda, Rui,Namba, Teruaki,Yoshimura, Tomohiro,Nakatsukasa, Masamichi,Nishiyama, Yutaka
, p. 1526 - 1531 (2013/02/23)
The reaction of benzanthrone and aryl magnesium bromides produced 6-aryl-substituted benzanthrones in moderate to good yields. Similarly, 6-alkylaminobenzanthrones were selectively prepared by the reaction of benzanthrone and lithium alkylamides. In contrast, for the lithium arylamides, the arylamino groups were selectively introduced at the 4-position of the benzanthrone.
General procedure for the synthesis of ortho-vinylbenzyl-substituted amines, ethers, and sulfides
Shcheglova,Kolesnik,Ashirov
, p. 1329 - 1334 (2013/11/06)
A convenient procedure has been proposed for the synthesis ortho-vinylbenzyl-substituted ethers, amines, and sulfides via reaction of o-(2-bromoethyl)benzyl bromide with various nucleophiles.
OPHTHALMIC COMPOSITIONS
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Page/Page column 4, (2012/05/07)
The present invention relates to compositions that may alleviate symptoms of ocular stress, as well as methods of their production, use, and storage compositions. The compositions comprise at least one ocular epithelial cell associating group and at least one hydrophilic group. In one embodiment the at least one ocular epithelial cell associating group and at least one hydrophilic group are substituents on a conjugated polyaromatic core. The compositions may be used in ophthalmic compositions and ophthalmic devices.
From allylic alcohols to chiral tertiary homoallylic alcohol: palladium-catalyzed asymmetric allylation of isatins
Qiao, Xiang-Chen,Zhu, Shou-Fei,Zhou, Qi-Lin
experimental part, p. 1254 - 1261 (2009/11/30)
A palladium-catalyzed asymmetric allylation of isatins with allylic alcohols as an allyl donor was developed by using chiral spiro phosphoramidite ligands. A variety of chiral tertiary homoallylic alcohols 3-allyl-3-hydroxy-2-oxindoles were prepared direc
NOVEL 2-SUBSTITUTED ALKYL-3-CARBOXY CARBAPENEMS AS ANTIBIOTICS AND A METHOD OF PRODUCING THEM
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, (2008/06/13)
The invention relates to new 2-substituted alkyl-3-carboxy carbapenems having the formula: with R1, R2, R3, X and Y defined hereafter as antibiotics and beta lactamase inhibitors produced by a novel Michael addition-elimination reaction of a substituted allyl azetidinone in the reaction shown: with R1, R2, Q, X and Y defined hereafter