New tartrate based cyclic phosphoric acids as organocatalysts in Mannich reactions
Keyword(s):
Abstract Cyclic phosphoric acids have attracted much attention as chiral organocatalysts. While binaphthol based ligands have been extensively used in various transformations, the analogous TADDOL-type ligands are less explored. A library of seventeen cyclic phosphoric acids with structural variation of the TADDOL backbone were synthesized and an optimization study of the Mannich reaction of aromatic N-(2-hydroxyphenyl)imines with 2,2-dimethyl-1-methoxy-silylenolate was performed. Enantioselectivities between 96% (S) and 70% (R) were observed and a rationalisation, based on crystal structure analysis and DFT calculations, is provided.
2015 ◽
Vol 26
(12-13)
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pp. 601-607
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2019 ◽
Vol 1176
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pp. 729-742
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2016 ◽
Vol 1118
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pp. 316-324
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1998 ◽
Vol 213
(3)
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