62941-99-5Relevant academic research and scientific papers
Synthesis of all stereoisomers and some congeners of isocytoxazone
Hamer?ak, Zdenko,?epac, Dragan,?iher, Dinko,?unji?, Vitomir
, p. 375 - 382 (2003)
cis-Isocytoxazone 2a and trans-isocytoxazone 2b, structural isomers of the antiasthmatic agent cytoxazone (-)-1, and their 5-substituted congeners 23-28 have been prepared. Aldol reaction of para-substituted benzaldehydes with 7-chloro-1-methyl-5-phenyl-1,4-benzodiazepin-2-one, followed by separation of diastereomeric racemates afforded 3-10. Acid-catalyzed 1,4-benzodiazepine ring opening, and transformation of the methyl esters of β-aryl-β-hydroxy-α-amino acids (11-16) via 4-methoxycarbonyl derivatives of 1,3-oxazolidin-2-one (17-22) and their reduction afforded the target oxazolidin-2-one derivatives 23-28. Racemic isocytoxazones 2a and 2b were prepared by an independent route starting from 4-methoxystyrene epoxide. Pure enantiomers of these diastereomeric racemates were separated by HPLC chromatography on chiral stationary phases. Their CD spectra, along with those of previously prepared enantiomers of cis-cytoxazone 1a and trans-cytoxazone 1b are discussed.
Photocatalytic Oxyamination of Alkenes: Copper(II) Salts as Terminal Oxidants in Photoredox Catalysis
Reed, Nicholas L.,Herman, Madeline I.,Miltchev, Vladimir P.,Yoon, Tehshik P.
supporting information, p. 7345 - 7350 (2018/11/25)
A photocatalytic method for the oxyamination of alkenes using simple nucleophilic nitrogen atom sources in place of prefunctionalized electrophilic nitrogen atom donors is reported. Copper(II) is an inexpensive, practical, and uniquely effective terminal oxidant for this process. In contrast to oxygen, peroxides, and similar oxidants commonly utilized in non-photochemical oxidative methods, the use of copper(II) as a terminal oxidant in photoredox reactions avoids the formation of reactive heteroatom-centered radical intermediates that can be incompatible with electron-rich functional groups. As a demonstration of the generality of this concept, it has been shown that diamination and deoxygenation reactions can also be accomplished using similar photooxidative conditions.
Novel synthesis of 4-carboxymethyl 5-alkyl/aryl oxazolidin-2-ones by rearrangement of 2-carboxymethyl 3-alkyl/aryl N-tert-butoxycarbonyl aziridines
Tomasini, Claudia,Vecchione, Andrea
, p. 2153 - 2156 (2008/02/09)
(matrix presented) A two-step approach for the diastereoselective synthesis of 4-carboxymethyl 5-alkyl/aryl oxazolidin-2-ones is described, which proceeds via the intermediate formation of 2-carboxymethyl 3-alkyl/aryl N-tert-butoxycarbonyl (N-Boc) aziridines. By reaction of N-Boc β-amino methyl esters with LiHMDS and iodine, trans 2,3-disubstituted N-Boc aziridines are obtained with high stereoselectivities and yields. The final rearrangement to oxazolidin-2-ones is achieved by treatment with a catalytic amount of a Lewis acid and proceeds with high yield and complete regio- and stereoselectivity.
