229964-68-5Relevant academic research and scientific papers
Hydrogen-Borrowing Alkylation of 1,2-Amino Alcohols in the Synthesis of Enantioenriched γ-Aminobutyric Acids
Hall, Christopher J. J.,Goundry, William R. F.,Donohoe, Timothy J.
, p. 6981 - 6985 (2021/03/01)
For the first time we have been able to employ enantiopure 1,2-amino alcohols derived from abundant amino acids in C?C bond-forming hydrogen-borrowing alkylation reactions. These reactions are facilitated by the use of the aryl ketone Ph*COMe. Racemisation of the amine stereocentre during alkylation can be prevented by the use of sub-stoichiometric base and protection of the nitrogen with a sterically hindered triphenylmethane (trityl) or benzyl group. The Ph* and trityl groups are readily cleaved in one pot to give γ-aminobutyric acid (GABA) products as their HCl salts without further purification. Both steps may be performed in sequence without isolation of the hydrogen-borrowing intermediate, removing the need for column chromatography.
Stereoselective formation and rearrangement of morpholinium ylides derived from copper carbenoids
Glaeske, Kevin W.,Naidu,West
, p. 917 - 920 (2007/10/03)
Amino diazoacetoacetates 4a-e and 7a,b were prepared from readily available amino alcohols and subjected to copper-catalyzed carbene-transfer reaction. Substrates 4c-e furnished the morpholin-2-ones 5c-e in good yield via the corresponding cyclic ammonium ylides, albeit with poor diastereoselectivity. Substrates 4a,b failed to provide the corresponding morpholinones, perhaps as a result of steric congestion. Cyclic substrates 7a,b underwent conversion to bicyclic morpholinones 8 and 9 in good yield and with moderate to good diastereoselectivity. This result is rationalized via control of the transiently stereogenic ammonium center of the intermediate bicyclic ylides.
Chirality transfer from carbon to nitrogen to carbon via cyclic ammonium ylides
Glaeske, Kevin W.,West
, p. 31 - 33 (2008/02/11)
(equation presented) Y=O,CH2; R=H,ME [e.r.=77:23->95:5 (R=H)] R1=Bn,prenyl; R2=Me,prenyl [d.r.=74:26->93:7 (R=Me)] Cyclic ammonium salts 2 were prepared by diastereoselective quaternization of nitrogen in the corresponding
