1008-29-3Relevant articles and documents
A convenient oxazole C-2 protecting group: The synthesis of 4- and 5-substituted oxazoles via metalation of 2-triisopropylsilyloxazoles
Miller, Ross A.,Smith, Randi M.,Marcune, Benjamin
, p. 9074 - 9076 (2005)
Metalation of oxazoles at the 4 and 5 position was achieved after regioselective C-2 silyl protection. Removal of the protecting group was then accomplished under mild conditions allowing for a straightforward preparation of C-5 monosubstituted and C-4,5
Unexpected intermolecular Pd-catalyzed cross-coupling reaction employing heteroaromatic carboxylic acids as coupling partners
Forgione, Pat,Brochu, Marie-Christine,St.-Onge, Miguel,Thesen, Kris H.,Bailey, Murray D.,Bilodeau, Francois
, p. 11350 - 11351 (2006)
Aryl-substituted five-membered heteroaromatics have attracted great interest over the past years due to their presence in a large number of pharmaceuticals and natural products. Recently, an advance in the preparation of these scaffolds was achieved by employing a C-H functionalization strategy. This method allows easy access to these biaryl motifs by precluding the necessity of preparing specific coupling partners, although poor regioselectivity is sometimes observed when more than one reactive C-H is present on the substrate. In an effort to circumvent this liability, we envisioned the use of a carboxylic acid moiety as a blocking group that could be later functionalized or removed. Remarkably, the coupling was found to occur exclusively at the position previously occupied by the acid, even in the presence of a reactive C-H group. This selective transformation was also found to proceed with other heteroaromatic carboxylic acids, allowing for the preparation of a variety of aryl-substituted heteroaromatics that would be difficult to obtain via other methods. Copyright
New FBPase inhibitors for diabetes
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Page/Page column 14, (2008/06/13)
Compounds of formula as well as pharmaceutically acceptable salts and esters thereof, wherein R1 to R3 have the significance given in the application and which can be used in the form of pharmaceutical compositions.
Photochemistry of 4- and 5- phenyl substituted isoxazoles
Pavlik, James W.,St. Martin, Heather,Lambert, Karen A.,Lowell, Jennifer A.,Tsefrikas, Vikki M.,Eddins, Cheryl K.,Kebede, Naod
, p. 273 - 281 (2007/10/03)
5-Phenylisoxazole (4) and 4-phenylisoxazole (22) underwent phototransposition to 5-phenyloxazole (5) and 4-phenyloxazole (24) respectively. Labeling with deuterium or methyl confirmed that these phototrans-positions occurred via the P4 pathway which involves only interchange of the N2 and C3 ring position. Thus, 4-deuterio-5-phenylisoxazole (4-4d), 4-methyl-5-phenylisoxazole (10), and 5-methyl-4-phenylisoxazole (23) phototransposed to 4-deuterio-5-phenyloxazole (5-4d), 4-methyl-5-phenyloxazole (11), and 5-methyl-4-phenyloxazole (25) respectively. In addition to phototransposition, isoxazoles 4, 10, and 23 also underwent photo-ring cleavage to yield benzoylacetonitrile (9), α-benzoylpropionitrile (15), and aceto-α-phenyl-acetonitrile (26) respectively. Irradiation of 5-phenyl-3-(trifluoromethyl)isoxazole (16) in acetonitrile led to 5-phenyl-2-(trifluoromethyl)oxazole (17), the P4 phototransposition product. Irradiation of 16 in methanol led to a substantial decrease in the yield of 17 and to the formation of a mixture of (E) and (Z)-2-methoxy-2- (trifluoromethyl)-3-benzoylaziridines 18a and 18b.
