Direct asymmetric three-component Mannich reactions catalyzed by a siloxy serine organocatalyst in water

A siloxy-l-serine organocatalyst has been developed to catalyze the asymmetric three-component Mannich reactions in the presence of water via a biphasic system, furnishing the Mannich products in good yields and high enantioselectivities.

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(2S)-2-Benzyloxycarbonylamino-3-(tert-butyl-diphenyl-silanyloxy)-propionic acidC19H25NO3Si[α]D23=+2.6 (c 1.94, MeOH)Source of chirality: Z-Serine-OHAbsolute configuration: (S)