- The Application of 1,2-Oxazinanes as Chiral Cyclic Weinreb Amide-Type Auxiliaries Leading to a Three-Component, One-Pot Reaction
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1,2-Oxazines were synthesised via a copper-catalysed aerobic acyl nitroso Diels-Alder reaction from 1,4-disubstituted 1,3-dienes and N-Boc-hydroxylamine. From this, 1,2-oxazinanes were obtained in a novel follow-up reaction path. The stability of several 1,2-oxazines and 1,2-oxazinanes towards organometallic compounds was tested to rate their operability as cyclic chiral Weinreb amide auxiliaries. 3,6-Di-tertbutyl-1,2-oxazinane gave the best results and was introduced as a chiral Weinreb amide-type auxiliary to yield chiral α-substituted ketones in a diastereomeric ratio of up to 98:2. The removal of the auxiliary can be performed with BuLi to form unsymmetrical α-chiral ketones. Thereafter, the chiral auxiliary can be re-isolated and purified by sublimation under vacuum.
- F?hrmann, Jan,Hermann, Ludmila,Hilt, Gerhard
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- Product Selectivity in KAHA Ligations: Ester vsAmide Formation with Cyclic Hydroxylamines
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Cyclic hydroxylamines form esters instead of the expected amides as major product upon reaction with α-ketoacids. In this report, we document a systematic investigation into the effect of the hydroxylamine structure and the solvent mixture on the product
- Rohrbacher, Florian,Baldauf, Simon,Wucherpfennig, Thomas G.,Bode, Jeffrey W.
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supporting information
p. 1929 - 1933
(2017/09/13)
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- Macrocyclic compounds and methods for their production
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There is provided inter alia compounds of formula (I): for use in treatment of viral infection or as an immunosuppressant.
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Page/Page column 68; 69
(2015/11/10)
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- FUSED BENZENE DERIVATIVE AND USE
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The present invention provides a compound represented by the general formula: [wherein Ring A represents an optionally substituted 5- to 8-membered ring, Ring B represents a further optionally substituted 4- to 10-membered ring, Ring C represents a further optionally substituted benzene ring, X1 represents carbon atom, X2 represents a carbon atom, an oxygen atom, etc., W represents a nitrogen atom, etc., Y11 represents a group represented by the formula CR2R3' (wherein R2 represents a hydrogen atom, a cyano group, a nitro group, etc., and R3' represents a hydrogen atom, a cyano group, a nitro group, etc., respectively), Y21 represents a group represented by the formula CR4R5' (wherein R4 represents a hydrogen atom, a cyano group, a nitro group, etc., and R5' represents a hydrogen atom, a cyano group, a nitro group, etc., respectively), etc., and R1 represents an electron-withdrawing group, respectively. The formula represents a single bond or a double bond] or a salt thereof, which is useful as an androgen receptor modulator.
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Page/Page column 47
(2010/02/12)
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