The efficient resolution of protected diols and hydroxy aldehydes by lipases: steric auxiliary approach and synthetic applications
摘要:
1,n-Diols (n = 2 - 5) and 2-hydroxy aldehydes protected with a steric auxiliary are transformed by Pseudomonas lipases with high enantioselectivity, thus allowing the efficient resolution of these molecules and the synthesis of related derivatives with high optical purity.
Combination of Metal-Catalyzed Cycloisomerizations and Biocatalysis in Aqueous Media: Asymmetric Construction of Chiral Alcohols, Lactones, and γ-Hydroxy-Carbonyl Compounds
作者:María J. Rodríguez-Álvarez、Nicolás Ríos-Lombardía、Sören Schumacher、David Pérez-Iglesias、Francisco Morís、Victorio Cadierno、Joaquín García-Álvarez、Javier González-Sabín
DOI:10.1021/acscatal.7b02183
日期:2017.11.3
The combination of the metal-catalyzed cycloisomerization of alkynes containing a tethered nucleophile as substituent in aqueousmedia (followed by the spontaneous hydrolysis, hydroalkoxylation, or aminolysis of the transiently formed five-membered heterocycles) with the subsequent enantioselective ketone bioreduction (mediated by KREDs) has been achieved. The overall transformations, which formally
Probing the Importance of the Hemilabile Site of Bis(phosphine) Monoxide Ligands in the Copper-Catalyzed Addition of Diethylzinc to <i>N</i>-Phosphinoylimines: Discovery of New Effective Chiral Ligands
作者:Isabelle Bonnaventure、André B. Charette
DOI:10.1021/jo800969x
日期:2008.8.1
hemilabile ligand Me-DuPHOS(O) 2 has proven to be a successful ligand for the copper-catalyzed addition of diethylzinc to N-phosphinoylimines. The corresponding α-chiral amines were obtained in high yields (80−98%) and enantiomeric ratios (19.0:1 to 99.0:1 er). Furthermore, this Cu•2 catalytic system has been shown to be effective in the addition of diethylzinc to nitroalkenes and in the reduction of β,β-disubstituted
Convergent Syntheses of 3,6-Dihydroxydec-4-enolides
作者:Jonathan C. Killen、Lorraine C. Axford、Sarah E. Newberry、Thomas J. Simpson、Christine L. Willis
DOI:10.1021/ol3018566
日期:2012.8.17
The total syntheses of the 3,6-dihydroxydecanolide from Cordyceps militaris and the novel C-3 epimer are reported using a diastereoselective Nozaki–Hiyama–Kishi reaction in the key cyclization to generate the 6R stereocenter.
Synthesis of New Optically Active Bis- and Tris(phosphines)
作者:Henri Brunner、Hans-Jürgen Lautenschlager
DOI:10.1055/s-1989-27368
日期:——
The synthesis of new optically active alkanediylbis- and alkanetriyltris(diphenylphosphines) is described. Easily accessible optically pure lactones and carboxylic acids are reduced to the alcohols, tosylated and reacted with lithium diphenylphosphide to give the corresponding phosphines.
A Comparison of Monocyclic and Bicyclic Phospholanes as Acyl-Transfer Catalysts
作者:E. Vedejs、O. Daugulis、L. A. Harper、J. A. MacKay、D. R. Powell
DOI:10.1021/jo030007+
日期:2003.6.1
The synthesis and evaluation of chiralphosphines 11, 15a, 19a, 24a, and 28a as nucleophilic catalysts for anhydride activation and kinetic resolution of alcohols is described. The relative reactivity follows the order 11a > 11b > 15a > 1 in the monocyclic series, and 24a > 19a > 28ain the bicyclic series, with an overall rate advantage of ca. 2 orders of magnitude for the bicyclic phospholanes over