18932-33-7Relevant articles and documents
The Silicon-Hydrogen Exchange Reaction: A Catalytic σ-Bond Metathesis Approach to the Enantioselective Synthesis of Enol Silanes
Zhou, Hui,Bae, Han Yong,Leutzsch, Markus,Kennemur, Jennifer L.,Bécart, Diane,List, Benjamin
, p. 13695 - 13700 (2020/08/24)
The use of chiral enol silanes in fundamental transformations such as Mukaiyama aldol, Michael, and Mannich reactions as well as Saegusa-Ito dehydrogenations has enabled the chemical synthesis of enantiopure natural products and valuable pharmaceuticals. However, accessing these intermediates in high enantiopurity has generally required the use of either stoichiometric chiral precursors or stoichiometric chiral reagents. We now describe a catalytic approach in which strongly acidic and confined imidodiphosphorimidates (IDPi) catalyze highly enantioselective interconversions of ketones and enol silanes. These "silicon-hydrogen exchange reactions"enable access to enantiopure enol silanes via tautomerizing σ-bond metatheses, either in a deprotosilylative desymmetrization of ketones with allyl silanes as the silicon source or in a protodesilylative kinetic resolution of racemic enol silanes with a carboxylic acid as the silyl acceptor.
Butyrophenones as hypotensive agents. Derivatives of 4 aryl 4 (hydroxymethyl)cyclohexylamine
Lednicer,Emmert,Rudzik,Graham
, p. 593 - 599 (2007/10/06)
The preparation of butyrophenone derivatives of 4 aryl 4 (hydroxymethyl) cyclohex 1 ylamines starting from the corresponding 4 cyano 4 phenylcyclohexan 1 ones is described. Substitution was varied in both rings; both isomers of 4 phenyl 4 (hydroxymethyl)cyclohex 1 ylamine were characterized. Those derivatives which carried p fluoro substitution on the butyrophenone exhibited hypotensive activity in the rat with diminished CNS activity compared to compounds lacking the hydroxymethyl group. The effect of substitution on the 4 aryl ring is discussed.