David J. Mathre, Ichiro Shinkai, Marek Zaidlewicz, Marek Krzemiński, Krzysztof Łączkowski. Tan. E. J. Corey, J. O. When stabilized BH3-THF (BTHF) was added to a mixture of ketone and tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaborole (MeCBS-ozaxaborolidine, MeCBS) catalyst 1, low enantioselectivities resulted. Efficient desymmetrisation of a meso-imide using a chiral oxazaborolidine catalyst. c Effect of the Secondary Reduction on the Enantioselectivity and Function of Additives in the Chiral Oxazaborolidine-Catalyzed Asymmetric Borane Reduction of Ketones. Thiruvengadam, Chou-Hong Tann, Dan Su. To whom correspondence should be addressed. These metrics are regularly updated to reflect usage leading up to the last few days. https://doi.org/10.1002/9781119600800.ch5, https://doi.org/10.3390/molecules23102408, https://doi.org/10.1016/j.tetlet.2016.04.091, https://doi.org/10.1016/j.tetasy.2015.02.011, https://doi.org/10.1002/047084289X.rt035s.pub3, https://doi.org/10.1016/B978-0-12-386537-3.00009-5, https://doi.org/10.1016/j.tetasy.2007.10.044, https://doi.org/10.1002/047084289X.rt035s.pub2, https://doi.org/10.1016/j.tetlet.2007.01.134, https://doi.org/10.1016/j.molcata.2005.08.055, https://doi.org/10.1016/j.tetasy.2006.01.011, https://doi.org/10.1201/9781420027303.ch16, https://doi.org/10.1016/j.tet.2004.10.067, https://doi.org/10.1070/RC2004v073n06ABEH000778, https://doi.org/10.1016/S0957-4166(03)00401-4, https://doi.org/10.1016/S0040-4039(03)01036-0, https://doi.org/10.1016/S0040-4039(02)02700-4, https://doi.org/10.1016/S0957-4166(02)00248-3. The relative free energies of TS1, 2, 3 and 4 are respectively 0.0, -6.9, -35.0 and -19.4 kcal/mol, which makes the overall rate limiting step TS1.If that is the case, then this explains why borane reduces only a carboxylic acid and not an ester. The enantioselective reduction of ketones using borane and a chiral oxazaborolidine as catalyst (CBS catalyst). Matthew Badland, Michael P. Burns, Robert J. Carroll, Roger M. Howard, Daniel Laity, Nathan J. Wymer. This 59, 8411-8414. David J. Mathre, Ichiro Shinkai, Marek Zaidlewicz, Marek Krzemiński, Krzysztof Łączkowski, Angela Patti, Sonia Pedotti. , 3 BH3-THF is typically only available in 1 M concentration. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Practical enantioselective reduction of ketones using oxazaborolidine The 114, 1906-1908. Find more information on the Altmetric Attention Score and how the score is calculated. Process Safety Evaluation and Scale-up of a Lactam Reduction with NaBH4 and TFA. Effect of borane source on the enantioselectivity in the enantiopure oxazaborolidine-catalyzed asymmetric borane reduction of ketones. enantioselective reduction of ketones using borane of interest in chemistry, biology, medicine. Related Reactions BH 3-THF. the Altmetric Attention Score and how the score is calculated. Mark Potyen,, Kanth V. B. Josyula,, Mike Schuck,, Sean Lu,, Peng Gao, and. Link, J. Noncatalytic Borane Reduction, a Nonneglectable Factor in the Reduction System. Reduction of a ketone leads to a secondary alcohol. Reaction details. Marco Bandini, Andrea Bottoni, Pier Giorgio Cozzi, Gian Pietro Miscione, Magda Monari, Rossana Pierciaccante, Achille Umani-Ronchi. Spiroborate esters in the borane-mediated asymmetric synthesis of pyridyl and related heterocyclic alcohols. An Efficient and Catalytically Enantioselective Route to (S)-(-)-Phenyloxirane You have to login with your ACS ID befor you can login with your Mendeley account. Effect of BF3 on the enantioselective reduction of trifluoromethyl ketones using a chiral lactam alcohol with borane. It reacts violently with water and alcohols, and so any reaction must exclude these common solvents. Stereoselective synthesis of morphine fragments trans- and cis-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolines. Robert C. Todd, M. Mahmun Hossain, Kanth V. Josyula, Peng Gao, John Kuo, C.T. 33 publications. Upon reaction parameter optimization, simultaneous addition of substrate and BTHF to MeCBS catalyst stabilizer resulted in the highest overall enantioselectivities (96% ee) and diminished the effect of the borohydride. The Synthesis of Two Potent β-3 Adrenergic Receptor Agonists. Ramón E. Huertas, Joseph A. Corella, John A. Soderquist. Usually, MeCBS is used (R'' = Me, but selectivity may be increased by varying this substituent). Chiral 1,3,2-oxazaborolidines in asymmetric synthesis: recent advances. Chem. Journal of Molecular Catalysis A: Chemical. The rates of the asymmetric borane reduction of prochiral ketones catalyzed by oxazaborolidines were substantially accelerated by organoaluminum compounds. Recoverable Fluorous CBS Methodology for Asymmetric Reduction of Ketones. Asaf R. Alimardanov,, Mark T. Barrila,, Frank R. Busch,, James J. Carey,, Michel A. Couturier, and. Process for preparing Ezetimibe intermediate by an acid enhanced chemo- and enantioselective CBS catalyzed ketone reduction. The product is a primary alcohol (RCOOH → RCH2OH). Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. Chemoselective C-Benzylation of Unprotected Anilines with Benzyl Alcohols Using Re2O7 Catalyst. Usually, MeCBS Int. Xiao Wang, Juanjuan Du, Han Liu, Da-Ming Du, Jiaxi Xu. and a chiral oxazaborolidine as catalyst (CBS catalyst). Y. Kawanami, S. Murao, T. Ohga, N. Kobayashi, Tetrahedron, 2003, Takashi Naka, Hiroki Ozawa, Ken-ichi Toyama, and Tadashi Shirasaka . Influences of Electronic Effects and Anions on the Enantioselectivity in the Oxazaborolidine-Catalyzed Asymmetric Borane Reduction of Ketones. Am. Enantioselective borane reduction of ketones catalyzed by tricyclic 1,3,2-oxazaborolidines. Borane (BH3) reagents are often able to selectively reduce carboxylic acids in the presence of esters. Boron Reagents in Process Chemistry: Excellent Tools for Selective Reductions. Soc., 1992, ][1,3,2]oxazaborole. When stabilized BH3-THF (BTHF) was added to a mixture of ketone and tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaborole (MeCBS-ozaxaborolidine, MeCBS) catalyst 1, low enantioselectivities resulted. You’ve supercharged your research process with ACS and Mendeley! Asymmetric oxazaborolidine-catalyzed reduction of prochiral ketones with N-tert-butyl-N-trimethylsilylamine–borane. New amine-stabilized deuterated borane–tetrahydrofuran complex (BD3–THF): convenient reagent for deuterium incorporations. Use of DOE for Rapid Development of a Red-Al Reduction Process for the Synthesis of 3,4-Isopropylidenedioxypyrrolidine Hydrotosylate.  Find more information about Crossref citation counts. Xiaoyong Fu, Timothy L. McAllister, T.K.