Synthesis of oxazolidines
A highly efficient one-pot synthesis of a wide range of 1,3-oxazolidines and 1,3-oxazinanes in high yields and with excellent enantioselectivities proceeds in the presence of a chiral magnesium phosphate catalyst via the formation of hemiaminal intermediates obtained by the enantioselective addition of respective alcohols to imines followed by intramolecular cyclization under mildly basic conditions.
S. K. Nimmagadda, Z. Zhang, J. C. Antilla, Org. Lett., 2014, 16, 4098-4101.
Tetrabutylammonium iodide as the catalyst and tert-butyl hydroperoxide in water (T-Hydro) as the oxidant enable a potential route for the construction of functionalized oxazolidines and imidazolidines via oxidative C(sp3)-H functionalization/C-O/C-N bonds formations. The reaction is simple, regioselective, and effective at moderate temperature with broad substrate scope.
V. Satheesh, M. Sengoden, T. Punniyamurthy, J. Org. Chem., 2016, 81, 9792-9801.
Bisphosphine-catalyzed mixed double-Michael reactions between amino-acid-derived pronucleophiles as Michael donors and electron-deficient acetylenes as acceptors afford β-amino carbonyl derivatives of oxazolidines, thiozolidines, and pyrrolidines in excellent yields and with high diastereoselectivities under operationally simple and mild conditions.
V. Sriramurthy, G. A. Barcan, O. Kwon, J. Am. Chem. Soc., 2007, 129, 12928-12929.
A stereoselective synthesis of 2,4- and 2,5-disubstituted 1,3-oxazolidines is accomplished via Pd-catalyzed carboamination of O-vinyl-1,2-amino alcohol derivatives. The transformations generate cis-disubstituted products with good to excellent diastereoselectivity, and enantiomerically enriched substrates are converted without loss of optical purity.
A. F. Ward, J. P. Wolfe, Org. Lett., 2011, 13, 4728-4731.
A palladium complex generated in situ from [Pd2(dba)3]·CHCl3 and a phosphoramidite ligand catalyzes an efficient enantioselective synthesis of 4-substituted-4-vinyloxazolidines through decarboxylative cycloaddition of vinylethylene carbonates with imines under mild reaction conditions in very good yields with high levels of enantio- and diastereoselectivities.
L. Yang, A. Khan, R. Zhen, L. Y. Jin, Y. J. Zhang, Org. Lett., 2015, 17, 6230-6233.