Academic literature on the topic 'Oxazolines chirales'

Manfred T. Reetz at the Max-Planck-Institut Mülheim and Philipps-Universität Marburg developed (J. Am. Chem. Soc. 2013, 135, 1665) a mutated Thermoethanolicus brockii alcohol dehydrogenase for the enantioselective reduc­tion of 4-alkylidene cyclohexanone 1. Using a new C₂-symmetic chiral bisphos­phine ligand (Wingphos, 5), Wenjun Tang at the Shanghai Institute of Organic Chemistry reported (Angew. Chem. Int. Ed. 2013, 52, 4235) the rhodium-catalyzed asymmetric hydrogenation of β-aryl enamide 3. Qi-Lin Zhou of Nankai University utilized chiral spirophosphine oxazoline iridium complexes 8a and 8b for the asymmetric hydrogenation of unsaturated piperidine carboxylic acid 6 (Angew. Chem. Int. Ed. 2013, 52, 6072) and 1,1-diarylethylene 9 (Angew. Chem. Int. Ed. 2013, 52, 1556) with excellent selectivities. The iron- catalyzed chemoselective hydrogenation of α,β-unsaturated aldehyde 11 was demonstrated (Angew. Chem. Int. Ed. 2013, 52, 5120) by Matthias Beller at the University of Rostock. Jeffrey S. Johnson at the University of North Carolina at Chapel Hill showed (J. Am. Chem. Soc. 2013, 135, 594) that asymmetric trans­fer hydrogenation of racemic acyl phosphonate 14 yielded β-stereogenic α- hydroxy phosphonate 16, a reversal in diastereoselectivity observed in the case of α-keto ester analogues. Gojko Lalic of the University of Washington developed (Org. Lett. 2013, 15, 1112) a monophasic copper catalyst system for the selective semireduction of terminal alkyne 17. Alois Fürstner and coworkers at Max-Planck-Institut Mülheim reported (Angew. Chem. Int. Ed. 2013, 52, 355) the ruthenium-catalyzed trans- selective hydro­genation of alkyne 19. Macrocyclic alkynes could also be selectively hydrogenated to E- alkenes using this methodology. Bernhard Breit at the University of Freiburg found (Angew. Chem. Int. Ed. 2013, 52, 2231) that a bimetallic Pd/ Re/ graphite catalyst system was highly active for the hydrogenation of tertiary amide 21 to amine 22. Professor Beller also discovered (Chem. Eur. J. 2013, 19, 4437) that a commercially available ruthenium complex allowed for the effective transfer hydrogenation of aromatic nitrile 23 to benzyl amine 24. Notably, no reductive amination side products were observed. Maurice Brookhart at the University of North Carolina at Chapel Hill used (Org. Lett. 2013, 15, 496) tris(pentafluorophenyl)borane as a highly active catalyst for the selective reduction of carboxylic acid 25 to aldehyde 26 with triethylsilane as a hydride source.

V. T. Perchyonok and Kellie L. Tuck of Monash University found (Tetrahedron Lett. 2008, 49, 4777) that a concentrated solution of Bu4NCl and H3PO2 in water effected free radical reductions and cyclizations. Stéphane G. Ouellet of Merck Frosst demonstrated (Tetrahedron Lett. 2008, 49, 6707) that an oxazoline such as 3 could be converted to the alcohol 4 by acylation followed by reduction. Elizabeth R. Burkhardt of BASF developed (Tetrahedron Lett. 2008, 49, 5152) a protocol for scalable reductive amination using an easily metered liquid pyridine-borane complex. Mohammad Movassaghi of MIT devised (Angew. Chem. Int. Ed. 2008, 47, 8909) a strategy for conversion of an allylic carbonate 8 by way of the allylic diazene to the terminal alkene 9. Philippe Compain of the Université d’Orleans uncovered (J. Org. Chem. 2008, 73, 8647) a practical procedure for oxidizing an inexpensive aldose such as 10 to the amide 12, a valuable chiral pool starting material. Karl A. Scheidt of Northwestern University extended (Organic Lett. 2008, 10, 4331) activated MnO2 oxidation to saturated aldehydes such as 13, leading to the ester 15. Tohru Fukuyama of the University of Tokyo showed (Organic Lett. 2008, 10, 2259) that halides such as 16 could be oxidized to the oxime 18 with the reagent 17. The product oximes are readily dehydrated to the corresponding nitriles. Chutima Kuhakarn of Mahidol University devised (Synthesis 2008, 2045) a simple protocol for the oxidation of a primary amine such as 19 to the nitrile 20 . Nasser Iranpoor and Habib Firouzabadi of Shiraz University developed (J. Org. Chem. 2008, 73, 4882) the reagent 22 for Mitsunobu coupling. The stereochemical course of this reaction with simple acyclic secondary alcohols such as 21 was not reported. Salvatore D. Lepore of Florida Atlantic University optimized (Angew. Chem. Int. Ed. 2008, 47, 7511) the quisylate 24 for the displacement with retention to give the azide 25. Hideki Yorimitsu and Koichiro Oshima of Kyoto University optimized (J. Am. Chem. Soc. 2008, 130, 11276) a Co catalyst for the conversion of a secondary halide such as 26 to the terminal alkene 27 . Base-mediated elimination gave primarily the internal alkene.