Catalyst‐Free Synthesis of Diastereomerically Pure 3‐Cyanoazetidin‐2‐ones via Thermally Promoted Tandem Wolff Rearrangement–Staudinger [2+2] Cycloaddition

2021 ◽  
Vol 6 (47) ◽  
pp. 13582-13588
Author(s):  
Ekaterina Levashova ◽  
Olga Bakulina ◽  
Dmitry Dar'in ◽  
Mikhail Krasavin
Synthesis ◽  
2020 ◽  
Author(s):  
Mikhail Krasavin ◽  
Judith Synofzik ◽  
Olga Bakulina ◽  
Olga Balabas ◽  
Dmitry Dar’in

A wide range of α-diazo-β-ketosulfones have been applied to thermally promoted tandem Wolff rearrangement – Staudinger [2+2] cycloaddition with imines to give polysubstituted β-lactam sulfones. Dia­stereomerically pure syn-diastereomers were obtained in good yields and the relative stereochemistry was confirmed by single-crystal X-ray crystallography. These findings significantly expand the scope of this transformation, in contrast to substantial limitations reported previously. Moreover, this methodology enables flexible exploration of new substitution patterns around the privileged β-lactam core for drug design and optimization.


2020 ◽  
Author(s):  
José Tiago Menezes Correia ◽  
Gustavo Piva da Silva ◽  
Camila Menezes Kisukuri ◽  
Elias André ◽  
Bruno Pires ◽  
...  

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.


2020 ◽  
Vol 17 (9) ◽  
pp. 709-716
Author(s):  
Ebrahim Saeedian Moghadam ◽  
Shahrzad Ghafary ◽  
Mohsen Amini

With regard to the importance of quinazoline as a privileged scaffold, herein we report the synthesis of twenty seven 2,4-disubstitute quinazoline derivatives in a new catalyst free condition. In the current work, poly ethylene glycol (PEG1000) as an inexpensive, very simple commercially available, ecofriendly and low melting point solvent was used. Air bubbling, a green oxidant, for oxidation purpose was also used. This is the first report about using PEG1000 as a solvent simultaneously with air bubbling as oxidant in quinazoline synthesis. All of the compounds 1-27 were synthesized in high yield with very simple work up and purification process without using column chromatography. All the structures were confirmed using 1H NMR, 13C NMR, IR, MS and elemental analysis.


Author(s):  
Mohammad Bakherad ◽  
Rahele Doosti ◽  
Ali Keivanloo ◽  
Mostafa Gholizadeh ◽  
Amir H. Amin

2020 ◽  
Vol 17 ◽  
Author(s):  
Visarapu Malathi ◽  
Pedavenkatagari Narayana Reddy ◽  
Pannala Padmaja

Abstract:: An efficient method has been developed for the synthesis of new pyrano[3,2-c] and pyrano[3,2-a]carbazole de-rivatives via a three component reaction of 4-hydroxycarbazole or 2-hydroxycarbazole, isocyanides, and dialkylacetylenedi-carboxylates. Noteworthy features of this protocol include mild reaction conditions, catalyst-free, high atom-economy and high yields.


2017 ◽  
Vol 4 (2) ◽  
pp. 168-172 ◽  
Author(s):  
Angelica de Fatima S. Barreto ◽  
Carlos Eduardo M. Salvador ◽  
Thaissa Pasquali F. Rosalba ◽  
Carlos Kleber Z. Andrade

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