Categories: Synthesis of N-Heterocycles >
Synthesis of pyrazolidines
A catalyst composed of Pd(OAc)2 and S-Phos allows the conversion of aryl chlorides as electrophiles in Pd-catalyzed alkene carboamination and carboetherification, minimizes N-arylation, and prevents formation of regiosisomieric mixtures. Various heterocycles, including pyrrolidines, isoxazolidines, tetrahydrofurans, and pyrazolidines, are efficiently generated with this method.
B. R. Rosen, J. E. Ney, J. P. Wolfe, J. Org. Chem., 2010, 75, 2756-2759.
The in situ generation of α-amino aldehydes followed by reaction with dimethyloxosulfonium methylide under Corey-Chaykovsky reaction conditions gives 4-hydroxypyrazolidine derivatives in high yields with excellent enantio- and diastereoselectivities. This organocatalytic sequential method enables an efficient synthesis of anti-1,2-aminoalcohols.
B. S. Kumar, V. Venkataramasubramanian, A. Sudalai, Org. Lett., 2012, 14, 2468-2471.