Synthesis of oxazolidinones
Synthesis of oxazolidin-2-ones derivatives was carried out starting from urea and ethanolamine reagents using microwave irradiation in a chemical paste medium in which a catalytic amount of nitromethane absorbs the microwaves and generates hot spots.
G. Bratulescu, Synthesis, 2007, 3111-3112.
An efficient, versatile and practical gram-scale preparation of oxazolidinone, imidazolidinone and dioxolanone is achieved.
N. Alouane, A. Boutier, C. Baron, E. Vrancken, P. Mangeney, Synthesis, 2006, 860-864.
An efficient sequential intramolecular cyclization of amino alcohol carbamates followed by Cu-catalyzed cross-coupling with aryl iodides under mild conditions gives N-aryl oxazolidinones in good yields. The reaction tolerated aryl iodides containing functionalities such as nitriles, ketones, ethers, and halogens. Heteroaryl iodides and substituted amino alcohol carbamates were can also be transformed.
W. Mahy, P. K. Plucinski, C. G. Frost, Org. Lett., 2014, 16, 5020-5021.
Carbonylimidazole derivatives are highly active acylation reagents for esterification and amidation in the presence of pyridinium salts as catalysts. These reactions are thought to involve both Brønsted acid and nucleophilic catalysis. This mode of activation has been applied to the synthesis of difficult to access oxazolidinones, as well as esters and amides.
S. T. Heller, T. Fu, R. Sarpong, Org. Lett., 2012, 14, 1970-1973.
Tetraarylphosphonium salts (TAPS) catalyze the [3 + 2] coupling reaction of isocyanates and epoxides to provide a range of oxazolidinones, including enantioenriched N-aryl-substituted oxazolidinones. These Brønsted acid/halide ion bifunctional catalysts accelerate epoxide ring opening with high regioselectivity.
Y. Toda, S. Gomyou, S. Tanaka, Y. Komiyama, A. Kikuchi, H. Suga, Org. Lett., 2017, 19, 5786-5789.
Concerted proton-coupled electron transfer (PCET) mediated by an excited state iridium complex enables amide activation in the presence of a weak phosphate base to furnish a reactive amidyl radical that readily adds to pendant alkenes. The thiophenol cocatalyst furnishes the product and regenerate the active forms of the photocatalyst.
D. C. Miller, G. J. Choi, H. S. Orbe, R. R. Knowles, J. Am. Chem. Soc., 2015, 137, 13492-13495.
A mild Pd-catalyzed ring-opening cyclization reaction of 2-vinylaziridines with an ambient atmosphere of carbon dioxide gives 5-vinyloxazolidinones in high yield as well as regio- and stereoselectivity.
F. Fontana, C. C. Chen, V. K. Aggarwal, Org. Lett., 2011, 13, 3454-3457.
An oxidative cleavage of alkyl C-Pd bond by H2O2 enables a palladium-catalyzed intramolecular aminohydroxylation to give various heterocycles with good yields and excellent diastereoselectivities. Facile transformation of these products provided a powerful tool toward the synthesis of 2-amino-1,3-diols and 3-ol amino acids. Preliminary mechanistic studies revealed that a SN2 type attack of water at a high-valent Pd center is involved.
H. Zhu, P. Chen, G. Liu, J. Am. Chem. Soc., 2014, 136, 1766-1769.
The use of Pd(OAc)2 and n-Bu4NOAc as catalysts enables an efficient and simple synthesis of oxazolidinones, oxazolidinthiones, imidazolidinthiones, and imidazolidinones from the corresponding propargylic starting materials in DCE at room temperature.
S. K. Alamsetti, A. K. Å. Persson, J.-E. Bäckvall, Org. Lett., 2014, 16, 1434-1437.
A mild and efficient gold(I)-catalyzed rearrangement of propargylic tert-butylcarbamates allows the synthesis of various 5-methylene-1,3-oxazolidin-2-ones, which would be less conveniently obtained using other methods.
A. Buzas, F. Gagosz, Synlett, 2006, 2727-2730.
Various N-Boc-protected alkynylamines are converted into the corresponding alkylidene 2-oxazolidinones or 2-oxazinones under very mild reaction conditions in the presence of a cationic Au(I) complex in high yield regardless of the substitution at nitrogen and alkyne terminus.
R. Robles-Machin, J. Adrio, J. C. Carretero, J. Org. Chem., 2006, 71, 4951-4955.
The use of a combination of silver acetate and N,N-dimethylaminopyridine enables a highly Z-selective syntheses of oxazolidin-2-ones from propargylic alcohols containing internal alkynes and phenyl isocyanate. The silver catalyst effectively activates the C≡C triple bond by acting as a π-Lewis acid to produce the corresponding oxazolidinones with high Z-selectivities.
K. Sekine, T. Mawatari, T. Yamada, Synlett, 2015, 26, 2447-2450.
A nickel-catalyzed cycloaddition of aziridines with isocyanates proceeded smoothly to give iminooxazolidine derivatives in good yields. A longer reaction time allowed the isomerization of the iminooxazolidine to the corresponding imidazolidinone derivatives.
T. Munegumi, I. Azumaya, T. Kato, H. Masu, S. Saito, Org. Lett., 2006, 8, 379-382.