Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline

• Xacobe C. Cambeiro,
• Rafael Martín-Rapún,
• Pedro O. Miranda,
• Sonia Sayalero,
• Esther Alza,
• Patricia Llanes and
• Miquel A. Pericàs

Beilstein J. Org. Chem. 2011, 7, 1486–1493, doi:10.3762/bjoc.7.172

• conversion versus time data for propanal; see Table 1, entry 1). Although not conclusive, these data suggest that the deactivation process is of a chemical nature, possibly due to the formation of an oxazolidinone between proline and the aldehyde [80][81][82], rather than a physical denaturation of the

Palladium-catalyzed formation of oxazolidinones from biscarbamates: a mechanistic study

• Benan Kilbas and
• Metin Balci

Beilstein J. Org. Chem. 2011, 7, 246–253, doi:10.3762/bjoc.7.33

• palladium catalyzed reaction furnished oxazolidinone derivatives in similar yields. It was shown that, if one face of the double bond is blocked by substituents such as H or CN, the reaction also takes place. On the basis of these results, it was assumed that an antiperiplanar orientation of the metal and

• nucleophile is not necessary to form oxazolidinones. The metal is probably bonded to the allylic system from the same face as the nucleophile. Keywords: bicyclic endoperoxides; biscarbamates; oxazolidinone; Pd-catalyzed allylic reaction; singlet oxygen; Introduction Palladium-catalyzed carbon–carbon bond

• formation reactions in synthetic organic chemistry have attracted considerable attention in recent years [1]. Palladium-catalyzed allylation is also a particularly useful method for the activation of allylic substrates [2]. Trost et al. described a highly stereoselective synthesis of oxazolidinone 2

Application of the diastereoselective photodeconjugation of α,β-unsaturated esters to the synthesis of gymnastatin H

• Ludovic Raffier and
• Olivier Piva

Beilstein J. Org. Chem. 2011, 7, 151–155, doi:10.3762/bjoc.7.21

• dienoate chain. The configuration at the C-2 carbon atom of this precursor was controlled by using a diastereoselective alkylation of an acyl oxazolidinone. In some cases, a Claisen condensation took place and afforded a β-ketoamide in noticeable amounts diminishing the overall yield of the sequence [15

Synthesis of a new class of aminocyclitol analogues with the conduramine D-2 configuration

• Latif Kelebekli,
• Yunus Kara and
• Murat Celik

Beilstein J. Org. Chem. 2010, 6, No. 15, doi:10.3762/bjoc.6.15

• . Photooxygenation of trans-7,8-diacetoxy- and cis-7,8-dichlorobicyclo[4.2.0]octa-2,4-diene afforded the bicyclic endoperoxides. Reduction of the latter with thiourea followed by a Pd(0) catalyzed ionization/cyclization reaction gave the corresponding oxazolidinone derivatives. Oxidation of the double bond with

• KMnO4 or OsO4 followed by acetylation gave the acetate derivatives, the exact configuration of which was determined by spectroscopic methods. Hydrolysis of the oxazolidinone rings and removal of the acetate groups furnished the desired aminocyclitols. Keywords: aminocyclitol; cyclitols; endoperoxide

• added to a solution of 5 mol % of the catalyst, prepared by stirring a mixture of ligand (triisopropylphosphite) and tris(dibenzylideneacetone)–dipalladium-chloroform complex in THF. Subsequent purification by column chromatography gave oxazolidinone 13 in 48% yield (Scheme 1). The structure of 13 was

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

Ru-catalyzed dehydrogenative coupling of carboxylic acids and silanes - a new method for the preparation of silyl ester

• Guo-Bin Liu and
• Hong-Yun Zhao

Beilstein J. Org. Chem. 2008, 4, No. 27, doi:10.3762/bjoc.4.27

• , hexamethyldisilazane, aminosilanes, N-trimethylsilylalkanamines, N-trimethylsilyl-2-oxazolidinone, N-trimethylsilylacetamide, or trialkylsilyl 2-methallylprop-2-ene-1-sulfinates have been extensively utilized for the transformation of carboxylic acids into the desired silyl esters [28][29][30][31][32][33][34][35][36