N-Phenyl substituent controlled diastereoselective synthesis of β-lactam-isatin conjugates
作者:Lalitha Gummidi、Nagaraju Kerru、Paul Awolade、Collins U. Ibeji、Rajshekhar Karpoormath、Parvesh Singh
DOI:10.1016/j.tetlet.2020.151602
日期:2020.3
Unprecedented diastereoselective synthesis of novel β-lactam-isatin conjugates via a Staudinger [2+2] cycloaddition is described. The electronic nature of substituents on the imine N-phenyl moiety induced high levels of stereocontrol and plausibly controlled the competition between direct ring closure (conrotatory) and isomerization of the azabutadiene intermediate. The presence of electron-donating
Studies in 1-Aza-1,3-butadienes: Diels-Alder Cycloaddition Reactions of 1,4-Diaryl-1-aza-1,3-butadienes with Aryl Sulphonyl Nitrosites Leading to the Synthesis of New Oxadiazines
作者:Kewal Krishan Singal、Baldev Singh、Baldev Raj
DOI:10.1080/00397919308020408
日期:1993.1
1,4-Diaryl-1-aza-1,3-butadienes (I) undergo a stereospecific 1,4-cycloaddition reaction with aryl sulphonyl nitrosites (II) generated 'in situ' by the reaction of aryl sulphinic acid and ethyl nitrite to yield six-membered cycloadducts characterized as 2-aryl sulphonyl-3,6-diaryl-2H,3H,6H-[1,2,3] oxadiazine derivatives(III) in good yield.
SINGAL, KEWAL KRISHAN;SINGH, BALDEV;REHALIA, KUSHAL SINGH, INDIAN J. CHEM. B. , 27,(1988) N, C. 843-845