[EN] PREPARATION OF SECONDARY AMINES WITH ELECTROPHILIC N-LINCHPIN REAGENTS [FR] PRÉPARATION D'AMINES SECONDAIRES AVEC DES RÉACTIFS ÉLECTROPHILES DE N-LINCHPINE
Unified Strategy to Amphenicol Antibiotics: Asymmetric Synthesis of (−)-Chloramphenicol, (−)-Azidamphenicol, and (+)-Thiamphenicol and Its (+)-3-Floride
The asymmetricsynthesis of (−)-chloramphenicol, (−)-azidamphenicol, and (+)-thiamphenicol and its (+)-3-floride, (+)-florfenicol, is reported. This approach toward the amphenicol antibiotic family features two key steps: (1) a cinchona alkaloid derived urea-catalyzed aldol reaction allows highly enantioselective access to oxazolidinone gem-diesters and (2) a continuous flow diastereoselective decarboxylation
Catalytic Asymmetric Formal [3+2] Cycloaddition of 2-Isocyanatomalonate Esters and Unsaturated Imines: Synthesis of Highly Substituted Chiral γ-Lactams
作者:Miguel Espinosa、Gonzalo Blay、Luz Cardona、M. Carmen Muñoz、José R. Pedro
DOI:10.1002/chem.201702777
日期:2017.10.20
Close the ring: The first asymmetric formal [3+2] cycloaddition involving 2-isocyanato esters and electrophilic alkenes is reported. Diisopropyl 2-isocyanatomalonate reacts with α,β-unsaturated N-(o-anisidyl) imines in the presence of a Mg(OTf)2–BOX complex to give highly substituted chiral pyrrolidinones with excellent yields and enantiomeric excesses up to 99 % (see scheme).
Catalytic Asymmetric Synthesis of Atropisomeric Nitrones: Versatile Intermediate for Axially Chiral Biaryls
作者:Wenjing Guo、Jian Gu、Zhenhua Gu
DOI:10.1021/acs.orglett.0c02830
日期:2020.10.2
and oximes is introduced. The reactions undergo selective N-arylation of oximes and provide an efficient protocol for the synthesis of atropisomeric nitrones. The optically active nitrones, serving as versatile intermediates, were converted to diversely functionalized axially chiral aniline derivatives and N-heterocycles.