TY - JOUR
T1 - Useful sialic acid modifications catalyzed by palladium
AU - Chang, Chih Wei
AU - Norsikian, Stéphanie
AU - Beau, Jean Marie
PY - 2009/5/18
Y1 - 2009/5/18
N2 - A stereo- and regioselective allylic substitution on simple N-acetylneuraminic acid (Neu5Ac2en) derivatives that ensures the control of the regio- and stereoselectivity and affords the C-2 or C-4 products with high efficiency, was studied. The Neu5Ac2en substrates were easily prepared from the peracetylated methyl ester 9 obtained by standard treatment overnight of the corresponding Neu5Ac methyl ester. Treatment of acetate 10 under Pd0-catalyzed allylic substitution conditions using sodium dimethylmalonate as a nucleophile failed to provide any alkylation product. The regioselectivity was largely improved to a synthetically useful level when using a more basic monophosphine ligand. A complete reversal of the regioselectivity occurred when the reaction was performed in the presence of bidentate phosphine. Selective transformations of these products provide easy entry to a variety of modified sialic acid derivatives, which can serve as useful sialyl building blocks for biological research.
AB - A stereo- and regioselective allylic substitution on simple N-acetylneuraminic acid (Neu5Ac2en) derivatives that ensures the control of the regio- and stereoselectivity and affords the C-2 or C-4 products with high efficiency, was studied. The Neu5Ac2en substrates were easily prepared from the peracetylated methyl ester 9 obtained by standard treatment overnight of the corresponding Neu5Ac methyl ester. Treatment of acetate 10 under Pd0-catalyzed allylic substitution conditions using sodium dimethylmalonate as a nucleophile failed to provide any alkylation product. The regioselectivity was largely improved to a synthetically useful level when using a more basic monophosphine ligand. A complete reversal of the regioselectivity occurred when the reaction was performed in the presence of bidentate phosphine. Selective transformations of these products provide easy entry to a variety of modified sialic acid derivatives, which can serve as useful sialyl building blocks for biological research.
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U2 - 10.1002/chem.200900093
DO - 10.1002/chem.200900093
M3 - Article
C2 - 19353608
AN - SCOPUS:67049118181
VL - 15
SP - 5195
EP - 5199
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 21
ER -