51-50-3Relevant articles and documents
Transition Metal-Catalysed Intramolecular Carbenoid C?H Insertion for Pyrrolidine Formation by Decomposition of α-Diazoesters
Solé, Daniel,Amenta, Arianna,Mariani, Francesco,Bennasar, M.-Llu?sa,Fernández, Israel
supporting information, p. 3654 - 3664 (2017/09/13)
The use of Pd-, Rh(II)- and Ru(II)-based catalysts has been explored in the transition metal-catalysed intramolecular carbenoid C?H insertion of α-diazoesters leading to pyrrolidines. Although the outcome of the reaction was highly substrate-dependent, in general, it was possible to control the chemoselectivity of the process towards pyrrolidines by adequate catalyst selection. The Pd(0)-catalysts were as efficient as [Rh(Ph3CCO2)2]2 in promoting the C(sp3)?H insertion of ortho-substituted anilines. In contrast, for anilines bearing meta- and para-substituents, the Rh(II)-catalyst provided the best chemoselectivities and reaction yields. On the other hand, [Ru(p-cymene)Cl2]2 was the most efficient catalyst for the insertion reaction of the N-benzyl-N-phenyl and N,N-dibenzyl α-diazoesters, while the C(sp3)?H insertion of the N-benzylsulfonamide substrate was only promoted by [Rh(Ph3CCO2)2]2. According to density functional theory (DFT) calculations, the mechanism involved in the Pd(0)- and Ru(II)-catalysed C(sp3)?H insertions differs considerably from that typically proposed for the Rh(II)-catalysed transformation. Whereas the Pd(0)-catalysed reaction involves a Pd-mediated 1,5-H migration from the C(sp3)?H bond to the carbenoid carbon atom leading to the formal oxidation of the transition metal, a Ru(II)-promoted Mannich type reaction involving a zwitterionic intermediate seems to be operative in the Ru(II)-catalysed transformation. (Figure presented.).
Synthesis of 2-Phenyl- and 2,2-Diarylpyrrolidines through Stevens Rearrangement Performed on Azetidinium Ions
Drouillat, Bruno,D'Aboville, Edouard,Bourdreux, Flavien,Couty, Fran?ois
supporting information, p. 1103 - 1109 (2015/10/05)
A set of azetidinium ions substituted at the nitrogen atom either by a benzyl group or a benzhydryl group were synthesized to delineate the scope of their ring expansion into 2-phenyl- or 2,2-diaryl-pyrrolidines through a Stevens rearrangement. Whereas th
Reversal agent and linker variants of reversed chloroquines: Activities against Plasmodium falciparum
Andrews, Simeon,Burgess, Steven J.,Skaalrud, Deborah,Kelly, Jane Xu,Peyton, David H.
supporting information; experimental part, p. 916 - 919 (2010/07/05)
We have shown that "reversed chloroquine molecules" constructed from chloroquine-like and resistance "reversal-agent"-like cores can be powerful drugs against malaria (J. Med. Chem. 2006, 49, 5623-5625). Several reversed chloroquines are now presented that probe parameters governing the activities against chloroquine-resistant and chloroquine-sensitive malaria strains. The design is tolerant to linker and reversal agent changes, but a piperazinyl group adjacent to the quinoline, at least for the group of compounds studied here, may be detrimental. 2009 American Chemical Society.
