Oxazolidinones, arylation

PREPARATION OF N-ARYL-5R-HYDROXYMETHYL-2-OXAZOLIDINONES FROM N-ARYL CARBAMATES N-PHENYL-(5R)-HYDROXYMETHYL- 2-OXAZOLIDINONE... 

Conditions for arylation of enolate equivalents have also been developed. In the presence of ZnF2, silyl enol ethers, silyl ketene acetals, and similar compounds react. For example, the TMS derivatives of /V-acyl oxazolidinones can be arylated. 

Palladium acetate in conjunction with a diphosphine ligand, xantphos, is active for arylation of amides, ureas, oxazolidinones and sulfonamides.174... 

Vinyl epoxides are highly useful synthetic intermediates. The epoxidation of dienes using Mn-salen type catalysts typically occurs at the civ-olefin. Epoxidations of dienes with sugar-derived dioxiranes have previously been reported to react at the trans-olefin of a diene. A new oxazolidinone-sugar dioxirane, 9, has been shown to epoxidize the civ-olefin of a diene <06AG(I)4475>. A variety of substitution on the diene is tolerated in the epoxidation, including aryl, alkyl and even an additional olefin. All of these substitutions provided moderate yields of the mono-epoxide with good enantioselectivity. 

Scheme 19 Mechanism of enantiomeric synthesis of aryl oxazolidinones...

The mechanism of the stereoselective syntheses of (K)-3-aryl-5-(hydroxy-methyl)oxazolidinones via the Mannenin reaction of aryl carbamic acid esters with (Jt)-glycidyl butyrate has been explored in detail by Brickner et al. [60]. Namely, N-lithiated carbamate derivatives of anilines are allowed to react with the commercially available (K)-glycidyl butyrate (96-98% enantiomeric excess ee) under appropriate conditions to obtain enantiomerically pure (Jt)-3-aryl-5-(hydroxymethyl)oxazolidinones in 85-99% yields, according the pathways depicted in Scheme 19. 

This class of rigid tricyclic fused oxazolidinones was synthesized in order to gain an understanding of the importance of the spatial relationship and torsional angle between the aryl and oxazolidinone rings with regard to antibacterial activity [51,65]. Considering the structure of an early lead compound,... 

Dup-721 (please see Fig. 2 for the structure), these tricyclic fused oxazolidinones have their aryl and oxazolidinone rings joined together by either one or two carbon linkers, resulting in the formation of the [6,5,5] and the... 

Fiuorinated aryl-oxazolidinone derivatives, for example, befloxatone 674... 

From detailed X-ray analysis and ab initio molecular orbital calculations, it has been suggested that the planar electron-rich aryl-oxazolidinone moiety interacts reversibly via the Ti-system with the flavin cofactor of the enzyme, which is also planar and known to be an electron acceptor [91]. Additionally, the side chains of the inhibitor, including the trifluoromethyl group, are engaged in interactions with the peptide core of the enzyme [87]. 

Alkyl- or 3-aryl-2,4-oxazolidinediones via photochemical cyclization, ° organonickel-mediated carbonylation, ° cyclization of A-alkenyl-a-acet-amides, ° carboxylation and cyclization of 2-propynamides, °" cyclization of (9-carbamates of a-hydroxy acetic acids and esters,cyclization of a-hydroxy acetamides,and catalytic asymmetric dihydroxylation (ADH) of A-alkenoyl-2-oxazolidinones. ... 

Phosphino-oxazoline)/Cu(II) complexes with bulky aryl groups at phosphorus were found to be excellent for a similar asymmetric cycloaddition reaction [39] (Eq. 8A.20). Enantioselectivity up to 79% ee was achieved in the cycloaddition of cyclohexadiene and acryloyl oxazolidinone. 

Du Y, Wu Y, Liu A-H et al (2008) Quaternary ammonium bromide functionalized polyethylene glycol a highly efficient and recyclable catalyst for selective synthesis of 5-aryl-2-oxazolidinones from carbon dioxide and aziridines under solvent-free conditions. J Org Chem 73(12) 4709-4712... 

Yang Z-Z, He L-N, Peng S-Y et al (2010) Lewis basic ionic liquids-catalyzed synthesis of 5-aryl-2-oxazolidinones from aziridines and C02 under solvent-free conditions. Green Chem 12(10) 1850-1854... 

Ketone 16 can be prepared from glucose in 6 steps without extensive chromatography purification (Scheme 10.5).78. V-Aryl-substituted oxazolidinone-containing ketone 18 can be synthesized... 

IBX-oxidations of unsaturated TV-aryl amides and urethanes proceed more efficiently and provide access to a substantial variety of pyrrolidinones and oxazolidinones, examples of which are shown in Scheme 92 (00AGE625, 01AGE202, 02JA2233). 

In this chapter, oxazole and its derivatives are named and numbered as in Chemical Abstracts. Thus compound (6) is called 4,5-dihydrooxazole rather than 2-oxazoline or A2-oxazoline, (7) is 2,5-dihydrooxazole, the betaines (3) are named anhydro-5-hydroxy-oxazolium hydroxides and not oxazolium 5-oxides or oxazolium 5-olates, and the oxo derivatives (4) and (5) are 5(4//)-oxazolone and 5(2//)-oxazolone, respectively, the position of the extra hydrogen atom being indicated in parentheses. The fully saturated compound (8) is oxazolidine its oxo derivatives are named oxazolidinones and oxazolidinediones, e.g. compound (9) is 2-oxazolidinone and (10) is 4,5-oxazolidinedione. A formula such as (11) is not meant to imply that all the substituents are methyl groups it represents a general oxazolidine derivative and is used in place of the cumbersome expression (12 R-R = H, alkyl or aryl). 

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