- I2-Catalyzed C-O Bond Formation and Dehydrogenation: Facile Synthesis of Oxazolines and Oxazoles Controlled by Bases
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A general method for the synthesis of oxazolines and oxazoles was developed through I2-catalyzed C-O bond formation and dehydrogenation with the same oxidant, TBHP. By simply tuning reaction bases, either oxazolines or oxazoles were selectively
- Gao, Wen-Chao,Hu, Fei,Huo, Yu-Ming,Chang, Hong-Hong,Li, Xing,Wei, Wen-Long
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supporting information
p. 3914 - 3917
(2015/08/18)
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- Synthesis of protected α-alkyl lanthionine derivatives
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Protected α-alkyl lanthionine derivatives were synthesized in five steps starting from a known phenyloxazoline precursor. This approach involved the synthesis of a family of substituted cyclic sulfamidates and their regioselective opening by nucleophilic attack with a protected cysteine. This efficient multistep strategy affords various α-alkylated lanthionine derivatives in high yields.
- Deno?l, Thibaut,Zervosen, Astrid,Lemaire, Christian,Plenevaux, Alain,Luxen, André
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p. 4526 - 4533
(2014/06/10)
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- Pd(ii)-catalyzed direct C5-arylation of azole-4-carboxylates through double C-H bond cleavage
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The first palladium-catalyzed direct C5-arylation of azole-4-carboxylates with simple unactivated arenes through double C-H bond cleavage is realized. This protocol provided a straightforward access to diverse 5-arylsubstituted azole-4-carboxylic derivatives with good functional group tolerance. The Royal Society of Chemistry 2012.
- Li, Ziyuan,Ma, Ling,Xu, Jinyi,Kong, Lingyi,Wu, Xiaoming,Yao, Hequan
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p. 3763 - 3765
(2012/06/15)
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- COMPOUNDS FOR TREATMENT OF CANCER
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The present invention relates to novel compounds having anti-cancer activity, methods of making these compounds, and their use for treating cancer and drug-resistant tumors, e.g. melanoma, metastatic melanoma, drug resistant melanoma, prostate cancer and drug resistant prostate cancer.
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Paragraph 0034; 00263
(2011/10/03)
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- Catalytic asymmetric hydrogenation of N-Boc-imidazoles and oxazoles
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Substituted imidazoles and oxazoles were respectively hydrogenated into the corresponding chiral imidazolines and oxazolines (up to 99% ee). The highly enantioselective hydrogenation was achieved by using the chiral ruthenium catalyst, which is generated
- Kuwano, Ryoichi,Kameyama, Nao,Ikeda, Ryuhei
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supporting information; experimental part
p. 7312 - 7315
(2011/06/24)
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- The use of phosphonium anhydrides for the synthesis of 2-oxazolines, 2-thiazolines and 2-dihydrooxazine under mild conditions
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β-Hydroxy amides 6 and 7 were treated with triphenylphosphonium anhydride trifluoromethane sulfonate (3), or the cyclic analogue 4, to generate 2-oxazolines 5 and 8 under mild conditions. The reaction was optimised by examining the number of equivalents of reagents 3 or 4, or diisopropylethyl amine required to best effect cyclisation. The effects of altering the reaction temperature, reaction time, concentration, solvent, and addition rate also were investigated. However, it was found that use of a trityl group to block reaction at the hydroxyl or thiol group of the starting amides, and subsequent in situ detritylation, in the absence of base, led to greatly improved yields. Reagent 4 offered significant advantages in the purification of products and was used to dehydrate a range of trityl derivatives to form simple oxazolines, thiazolines, and a dihydro-1,3-oxazine, in high yield (85-99%), as well as a tetrahydro-1,3-oxazepine (31%).
- Petersson, Maria J.,Jenkins, Ian D.,Loughlin, Wendy A.
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experimental part
p. 739 - 746
(2009/06/20)
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- Solid-phase synthesis of α-alkylserines via phase-transfer catalytic alkylation of polymer-supported 2-phenyl-2-oxazoline-4-carboxylate
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Described is the development of a new solid-phase synthetic method for α-alkylserines in which phase-transfer catalytic alkylation of polymer-supported 2-phenyl-2-oxazoline-4-carboxylate (12) is the key step. The easy preparation of the polymer-supported
- Lee, Jihye,Ha, Min Woo,Kim, Taek-Soo,Kim, Mi-Jeong,Ku, Jin-Mo,Jew, Sang-sup,Park, Hyeung-geun,Jeong, Byeong-Seon
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experimental part
p. 8839 - 8843
(2009/12/26)
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- A flexible synthetic approach to the hennoxazoles
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Three advanced intermediates corresponding to the carbon skeleton of the hennoxazoles have been prepared. Central to the strategy is the synthesis of the oxazoles prior to coupling with the other fragments and a dithiane addition to allow for the generati
- Zylstra, Eric J.,She, Miles W.-L.,Salamant, Walter A.,Leahy, James W.
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p. 623 - 627
(2007/10/03)
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- Synthesis of functionalized oxazolines and oxazoles with DAST and Deoxo-Fluor.
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[formula: see text] A mild and highly efficient cyclization of beta-hydroxy amides to oxazolines is described using DAST and Deoxo-Fluor reagents. A one-pot protocol for the synthesis of oxazoles from beta-hydroxy amides is also presented.
- Phillips,Uto,Wipf,Reno,Williams
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p. 1165 - 1168
(2007/10/03)
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- Electrophilic ring opening of oxazolines derived from serine and threonine: A practical entry to N(N)-protected β-halogeno α-aminoesters
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Treatment of oxazolines 4a-c derived from serine or threonine with chloroformates, leads to the oxazoline ring opening and to the formation of N,N-protected β-chloro-α-aminoesters la-e in 30-88% isolated yields. In the presence of NaI (0.9 equiv), oxazolines 4a,b,d react with ethyl chloroformate to afford the N,N-protected β-iodo α-amino esters 1f-h (67-89% yields), whereas the reaction of 4a,b with trimethylsilyl halide gives the analogous N-benzoyl β-halogeno derivatives 1i,k with 30-86% yields.
- Laaziri, Abdelhamid,Uziel, Jacques,Juge, Sylvain
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p. 437 - 447
(2007/10/03)
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- Oxidation of oxazolines and thiazolines to oxazoles and thiazoles. Application of the Kharasch-Sosnovsky reaction
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Using a modification of the Kharasch-Sosnovsky reaction, the oxidation of oxazolines and thiazolines bearing a variety of 2-alkyl substituents (chiral and achiral) were smoothly oxidized to their corresponding oxazoles and thiazoles, respectively. The key feature involved in the successful implementation of this important oxidation was the use of a mixture of Cu(I) and Cu(II) salts to enhance the oxidation of the intermediate captodative radical, 24. The main limitation of this method was shown when the oxidation failed with oxazolines/thiazolines lacking the carboalkoxy group at C-4.
- Meyers,Tavares, Francis X.
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p. 8207 - 8215
(2007/10/03)
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- Stereoselective Cycloaddition of Nitrile Oxides to 4-Vinyl-Oxazolines and -Oxazolidines
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Cycloaddition of nitrile oxides to 4-vinyl-2-oxazoline 1 and to 4-vinyloxazolidine 2 afford diastereomeric mixtures of 2-isoxazolines in which the erythro product predominates (32-64percent d.e.).In contrast, the corresponding reactions with acyclic analogue 3 favoured the threo-adducts and were less selective (8-20percent d.e.).Key Words: 1,3-dipolar cycloaddition; nitrile oxides; isoxazolines
- Boyd, Ewan C.,Paton, R. Michael
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p. 3169 - 3172
(2007/10/02)
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- A MILD PROCEDURE FOR THE PREPARATION OF 2-OXAZOLINES
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A general procedure using triphenylphosphine and diethylazodicarboxylate to prepare 2-oxazolines is described.
- Roush, David M.,Patel, Manorama M.
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p. 675 - 680
(2007/10/02)
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- Von der basenkatalysierten Ringoeffnung von 2H-Azirinen zu einer α-Alkylierungsmethode von primaeren Aminen
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It is shown than fluorene-9'-spiro-2-(3-phenyl-2H-azirine) (1) on treatment with various alcohols in the presence of the corresponding alkoxide ions yields N-(9'-fluorenyl)benzimidates 2a-d (Scheme 1). 2,2,3-Triphenyl-2H-aziridine (3) reacts with methanol in a similar manner (Scheme 2).Benzimidates 2a (Scheme 3), 8 (Scheme 4) and 10 (Scheme 5) can easily be deprotonated by butyllithium (BuLi) or lithium diisopropylamide (LDA) in tetrahydrofuran (THF) to 1-methoxy-2-aza-allylanions, that can be alkylated, at C(3), exclusively, by various electrophiles (e.g.R-X (X = I, Br), RCHO or methyl acrylate (see also Scheme 6)).As the acidic hydrolyses (1 N HCl) of benzimidates 9 and 11 leads to the corresponding α-alkylated free amines 15 and 18 (Scheme 7 and 8), benzoyl derivatives 16 and 19 are obtained from the hydrolysis under basic conditions.On the other hand it is observed that a catalyzed Chapman rearrangement of 9 and 11 results in the formation of N-benzoyl-N-methyl derivatives 17 and 20 (Scheme 7 and 8).The described reactions offer a simple method for the α-alkylation of actived primary amines.
- Schulthess, Adrian Heinz,Hansen, Hans-Juergen
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p. 1322 - 1336
(2007/10/02)
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