Theoretical studies on enantioselective reduction of ketone with borane catalyzed by a B-methoxy-oxazaborolidine catalyst derived from pinene have been performed by means of the density functional theory (DFT) method. We are sorry that this page was not useful for you! Struct Chem 24:485–1492, Ujaque G, Lee PS, Houk KN, Hentemann MF, Danishefsky SJ (2002). Tetrahedron Asym 20:1020–1026, Krzemiński MP, Wojtczak A (1996). Copyright © 2020 Elsevier B.V. or its licensors or contributors. Google Scholar, Hirao A, Itsuno S, Nakahama S, Ito K (1983). Angew Chem Int Ed Engl 37:1986, Liu H, Xu JXJ (2006). Wiley, New York, Gonzalez C, Schlegel HB (1990). Jmol.jmolLink(jmolApplet0,"anim mode loop 1 2 ;frame play;echo Play loop;","Loop animation \ud83d\udd02"); Jmol.jmolLink(jmolApplet0,"anim off;echo ","Stop animation \u23F9"); Jmol.jmolLink(jmolApplet0,"anim rewind#;","Frame 1 \u23EB");Jmol.jmolHtml('    ') Google Scholar, Wei D, Tang M, Zhao J, Sun L, Zhang W, Zhao C, Zhang S, Wang H (2009). Jmol.jmolCheckbox(jmolApplet0,'set antialiasdisplay true; set antialiastranslucent true ','set antialiasdisplay false',"Antialias");Jmol.jmolButton(jmolApplet0,"draw pointgroup;","Show All Symmetry Elements"); Home / Organic Reactions / Enantioselective reagents / Enantioselective Ketone Reduction Chiral Reagent – Alpine Borane, Click the reaction arrows in sequence to view the 3D models and animations respectively. document.write("   ") This mechanism is in good agreement with the current experimental facts, and also explains why ketone reduction affords different products at different conditions. Aside from effectively keeping low concentrations of the borane source (i.e. Tetrahedron Asymm 13:1347–1349, Glushkov VA, Tolstikov AG (2004). Kettouche, H.S. It is mandatory to procure user consent prior to running these cookies on your website. Rev., 1989, 89, 1553–1561. R-Alpine borane is effective at reducing acetylenic ketones to secondary alcohols with reasonable enantioselectivity. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are as essential for the working of basic functionalities of the website. Copyright © 1996 Published by Elsevier Ltd. https://doi.org/10.1016/0957-4166(96)00147-4. These cookies do not store any personal information. Tetrahedron Asym 3:1475–1504, Deloux L, Srebnik M (1993). Angew Chem Int Ed 37:1986–2012, Wallbaum S, Martens J (1992). Subscription will auto renew annually. J Chem Soc Chem Commun 0:315–317, CAS  Cite this article. 4, 14, 15 The MLC mechanism denotes that both the TM center and ligand get involved in the hydrogenation. Jmol.jmolCheckbox(jmolApplet0,"zoom 300","zoom 100","Zoom",false);Jmol.jmolBr() You also have the option to opt-out of these cookies. All the structures were optimized completely using wB97XD/6-31G(d,p) level and the mechanism of the enantioselective reduction is studied. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. © 2020 Springer Nature Switzerland AG. ChemTube3D.com uses cookies to improve your experience. R-Alpine borane is effective at reducing acetylenic ketones to secondary alcohols with reasonable enantioselectivity.The enantioselection arises through the selective placement of the sterically undemanding alkyne close to … Mechanism of the Corey-Bakshi-Shibata Reduction. A DFT study on the reaction mechanism of enantioselective reduction of ketones with borane catalyzed by a B-methoxy-oxazaborolidine catalyst derived from (–)-β-pinene. Laboratoire des produits naturels d’origine végétale et de synthèse organique, Département de Chimie, Université Frères Mentouri - Constantine 1, Constantine, Algeria, You can also search for this author in Experimental Analysis of the Catalytic Cycle of the Borane-Promoted Imine Reduction with Hydrosilanes: Spectroscopic Detection of Unexpected Intermediates and a Refined Mechanism. This is a preview of subscription content, log in to check access. NCI analysis of the four computed transition states associated with stereoselectivity-determining step discloses that TS3a(S) is the stable conformation with respect to TS3a(R), TS3b(S), and TS3b(R). But opting out of some of these cookies may have an effect on your browsing experience. Ed., 1998, 37, 1986-2012.DOI) portrays the rationale for the enantioselectivity and high reaction rates, which are influenced only by the CBS catalyst.This catalyst is a combination of both a Lewis acid and a chiral auxiliary! Jmol.jmolLink(jmolApplet0,"select all;spacefill off; wireframe .1;","Sticks")