regiodivergent and stereoselective ring-opening isomerization of vinylcyclopropane was developed with cobalt catalysis. Employing the commercially available Xantphos ligand, the reactions afforded exclusively linear-type 1,3-dienes as the products. Interestingly, when switching the ligand to an amido-diphosphine ligand (PNP), branched-type 1,3-dienes were obtained with high regioselectivity and stereoselectivity
Synthesis of New Pyrazoline-Nucleoside Analogue Derivatives
作者:M. Azouz、K. Lammara、M. Benallia、H. Guenane
DOI:10.1080/15257770.2013.786834
日期:2013.1
In this work, a synthesis of pyrazoline nucleosides analogues is presented, using the stereospecific sodium salt glycosylation procedure. In the first step, chalcones were prepared using Claisen-Schmidt reaction by reacting benzaldehyde with enolizable ketones in ethanolic NaOH solutions. Next, these chalcones were immediately reacted with hydrazine hydrochloride in the presence of dry methanol to obtain the corresponding 2-pyrazolines. Finally, the coupling of the pyrazolines with 1-chloro-arabinofuranose leads to different beta-nucleosides as the major product (13-17) in good yields.The structures of these derivatives were characterized by infrared and (HNMR)-H-1 spectroscopy and mass spectrometry.
Doods et al., Proceedings of the Royal Society of London. Series B, Biological sciences, 1953, vol. 140, p. 470,481
作者:Doods et al.
DOI:——
日期:——
Formation of 2,4-diaroyl-3,5-diarylthiolanes from chalcones and polysulfide. Scope, conditions, and the thiolane NMR
作者:Robert T. LaLonde、Benjamin A. Horenstein、Kit Schwendler、Richard C. Fritz、Robert A. Florence、Irena Ekiel、Ian C. P. Smith
DOI:10.1021/jo00170a035
日期:1983.11
Dodds et al., Proceedings of the Royal Society of London. Series B, Biological sciences, 1953, vol. 140, p. 470,482