Stereoselective TiCl4-mediated aldol reactions starting from acylsilanes.

Gangababu Marri (1) , J. Satyanarayana Reddy (1) , Johal Ruiz (2) , Saibal Das (1) , Rene Gree (2)

1 Division of Natural Products Chemistry
2 ISCR - Institut des Sciences Chimiques de Rennes

A simple and efficient method for the prepn. of β-hydroxyacylsilanes has been developed through a TiCl4-mediated aldol reaction of acylsilanes with aldehydes. Acylsilane EtCOSiMe2Ph reacted with PhCHO giving 80:20 diastereomeric syn-anti mixt. of PhCH(OH)CHMeCOSiMe2Ph under TiCl4 catalysis. Similarly, arom. aldehydes contg. electron-withdrawing substituents, and isobutyraldehyde iPrCHO gave the hydroxyacyl silanes RCH(OH)CHMeCOSiMe2Ph with reasonable yields and high syn-selectivity. A selection of Lewis acids has been assessed, and other parameters such as solvent and temp. have been optimized. These aldol reactions occur under mild conditions and furnish a selection of β-hydroxy acylsilanes in fair-to-good yields with high syn selectivities (up to 99 %).

Domains: Life Sciences [q-bio]; Toxicology; Ecotoxicology

Gangababu Marri, J. Satyanarayana Reddy, Johal Ruiz, Saibal Das, Rene Gree. Stereoselective TiCl4-mediated aldol reactions starting from acylsilanes.. European Journal of Organic Chemistry, 2015, 2015 (4), pp.840--846. ⟨10.1002/ejoc.201403263⟩. ⟨hal-01146438⟩