Journal ArticleDOI
A stable and easily prepared catalyst for the enantioselective reduction of ketones. Applications to multistep syntheses
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In this paper, the authors described a new method for the catalytic enantioselective reduction of ketones to chiral secondary alcohols, where the stoichiometric reagent in the reduction is borane and the catalyst is a chiral oxazaborolidine such as 1 (0.05-0.1 molfmol of ketone).Abstract:
We have recently described a new method for the catalytic enantioselective reduction of ketones to chiral secondary alcohols.' The stoichiometric reagent in the reduction is borane (usually 0.6 molfmol of ketone), and the catalyst is a chiral oxazaborolidine such as 1 (0.05-0.1 molfmol of ketone). Excellent enantioselectivities, easy recoverability of the chiral catalyst predecessor, near quantitative yields, short reaction times (a few minutes at 23 \"C), and predictability of the absolute configuration of the product contribute to the outstanding utility of this (CBS') process. This paper reports several subsequent developments in this area with respect to improved practicality and important applications. In contrast to 1 which is both air and moisture sensitive, the B-methylated oxazaborolidine 2 can be stored in closed containers at room temperature and weighed or transferred in air. Catalyst 2 is also much more easily prepared than 1. Reaction of (S)-read more
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Convergent total synthesis of the racemic HIF-1 inhibitor laurenditerpenol
Michael E. Jung,G-Yoon J. Im +1 more
TL;DR: The convergent total synthesis of the HIF-1 inhibitor laurenditerpenol 1a was reported in this paper, where the key step is the Julia olefination-reduction process between the two components, the sulfone 4 (prepared from the dimethylfuran-maleic anhydride Diels-Alder adduct) and the aldehyde 3 (composed from 3-methylcyclohexenone).
Design, synthesis, and evaluation of curcumin-derived arylheptanoids for glioblastoma and neuroblastoma cytotoxicity
Catherine A. Campos,Joseph B. Gianino,Barbara J. Bailey,Mary E. Baluyut,Constanze Wiek,Helmut Hanenberg,Harlan E. Shannon,Karen E. Pollok,Brandon L. Ashfeld +8 more
TL;DR: The present findings indicate that these curcumin analogs are viable lead compounds for the development of new central and peripheral nervous system cancer chemotherapeutics with the potential for little effects on normal hematopoietic progenitor cells.
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β‐Ketoesters as Mono‐ or Bisnucleophiles: A Concise Enantioselective Total Synthesis of (−)‐Englerin A and B
Lei Guo,Bernd Plietker +1 more
TL;DR: A short enantioselective total synthesis of englerin A, a guaiane sesquiterpene with significant in vitro antitumor activity, is reported, generating the optically pure natural product in 6.7 % overall yield over twelve steps starting from methylglyoxal.
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Diazaborolidines, a new class of enantioselective organoboron catalytic agents.
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Journal ArticleDOI
Asymmetric Synthesis of Inhibitors of Glycinamide Ribonucleotide Transformylase
TL;DR: It is revealed that both diastereomers of 10-methylthio-DDACTHF are potent inhibitors of rhGAR Tfase that exhibit effective cell growth inhibition, which is dependent on intracellular polyglutamation by folylpolyglutamate synthetase but not intrACEllular transport by the reduced folate carrier.
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Book
Molybdenum and Molybdenum-Containing Enzymes
TL;DR: In this article, a few moment to read a book even only few pages is recommended, even if it is not obligation and force for everybody, reading book becomes a choice of your different characteristics.
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