- Construction of chiral α-amino quaternary stereogenic centers via phase-transfer catalyzed enantioselective α-alkylation of α-amidomalonates
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An efficient enantioselective synthetic method for α-amido-α-alkylmalonates via phase-transfer catalytic α-alkylation was successfully developed. The α-alkylation of α-amidomalonates under phase-transfer catalytic conditions (50% KOH, toluene, 40 °C) in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide afforded the corresponding α-amido-α-alkylmalonates in high chemical yields (up to 99%) and optical yields (up to 97% ee), which could be readily converted to versatile chiral intermediates bearing α-amino quaternary stereogenic centers. The synthetic potential of this methodology was demonstrated via the synthesis of chiral azlactone, oxazoline, and unnatural α-amino acid.
- Ha, Min Woo,Lee, Myungmo,Choi, Sujee,Kim, Seek,Hong, Suckchang,Park, Yohan,Kim, Mi-Hyun,Kim, Taek-Soo,Lee, Jihoon,Lee, Jae Kyun,Park, Hyeung-Geun
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p. 3270 - 3279
(2015/03/30)
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- METHODS FOR CONJUGATING NUCLEIC ACIDS WITH SMALL MOLECULES
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A method for conjugating a nucleic acid with a molecule is provided. The method includes steps of (a) reacting the nucleic acid having a 5′-monophosphate with an activating agent in a first buffer to form a solution; (b) mixing an alcohol with the solution formed in the step (a) to obtain an intermediate; and (c) dissolving the intermediate in a second buffer containing an ethylenediaminetetraacetic acid (EDTA) and adding a nucleophile thereinto to react the intermediate with the nucleophile.
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- Synthetic Studies Relevant to Biosynthetic Research on Vitamin B12. Part 10. Construction of the East and West Building Blocks for Synthesis of Isobacteriochlorins
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Studies with model compounds have led to the development of effective methods for (a) linking the pyrrolic rings to the reduced rings present in the isobacteriochlorin system (e.g. 4) and (b) for introducing the carbon at C-5 required to complete the macr
- Battersby, Alan R.,Block, Michael H.,Fookes, Christopher J. R.,Harrison, Peter J.,Henderson, Graeme B.,Leeper, Finian J.
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p. 2175 - 2188
(2007/10/02)
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