Categories: Synthesis of N-Heterocycles, Synthesis of O-Heterocycles >
Synthesis of isoxazolidines and benzisoxazolines
Recent Literature
The oxidative intramolecular bromo-amination of various N-alkenyl
sulfonamides and N-alkenoxyl sulfonamides via umpolung of alkali metal
bromides occurred exo-selectively to generate pyrrolidines and isoxazolidines
in high yields with good diastereoselectivities. This method provided the
desired products with a low amount of organic waste.
K. Moriyama, Y. Izumisawa, H. Togo, J. Org. Chem., 2011,
76, 7249-7255.
A chiral Ti(IV) catalyst can be successfully utilized in the asymmetric
1,3-dipolar cycloaddition reactions between various nitrones and acrolein to
give the corresponding endo cycloadducts (isoxazolidines) with high to
excellent enantioselectivities.
T. Kano, T. Hashimoto, K. Maruoka, J. Am. Chem. Soc., 2005, 70, 11926-11927.
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.
A broad range of substituted benzisoxazolines have been synthesized by a mild [3
+ 2] cycloaddition of nitrones and arynes. The process tolerates various
functional groups.
C. Lu, A. V. Dubrovskiy, R. C. Larock, J. Org. Chem., 2012,
77, 2279-2284.
