Sila–pharmaca. Part 32. Crystal and molecular structures of the (R)-enantiomer and the racemate of the antimuscarinic agent (cyclohexyl)phenyl[2-(pyrrolidin-1-yl)ethyl]silanol (sila–procyclidine)

Abstract

Enantiomer and the Racemate of the Antimuscarinic Agent (Cyclohexy1)phenyl[Z-(pyrrolidin-I -yl)ethyl]silanol (Sila-Procyclidine) t

Enantioselective reduction of acetyldimethylphenylsilane by Trigonopsis variabilis (DSM 70714)

“…at the moment, which are structurally related to 1 and 7, respectively (Tacke et al 1985), to learn about the influence of the substituents attached to silicon and germanium on reaction speed and stereoselectivity. It is of interest to see whether the stereochemistry of these biotransformations is in agreement with Prelog's rule (Prelog 1964).…”

“…Several methods have been employed to prepare optically active silicon compounds including resolution through separation of diastereomers, kinetic resolution, asymmetric synthesis, as well as stereospecific reactions starting from resolved compounds (Corriu and Guerin 1982;Corriu et al 1984). Recently, it was shown for the first time that biotransformationsarealso useful for preparing optically active organosilicon compounds: Some microorganisms were found to reduce carbonyl groups of various organosilicon substrates stereoselectively to give the corresponding optically active alcohols (Tacke et al 1983;Tacke et al 1984;Tacke et al 1985;Tacke and Zilch 1986a;Syldatk et al 1986). One of these bioconversions is the enantioselective reduction of acetyldimethylphenylsilane {1) to give (R)-(1-hydroxyethyl)dimethylphenylsilane [(R)-2].…”

“…In recent years there has been increasing interest in optically active organosilicon compounds with respect to their use as reagents in asymmetric organic synthesis (Larson and Torres 1985) and as drugs in experimental pharmacology (Sheldrick et al 1985;Tacke and Zilch 1986a, b). Several methods have been employed to prepare optically active silicon compounds including resolution through separation of diastereomers, kinetic resolution, asymmetric synthesis, as well as stereospecific reactions starting from resolved compounds (Corriu and Guerin 1982;Corriu et al 1984).…”

The First Liquid-Chromatographic Separation of the (R)- and (S)-Enantiomers of a Chiral Silanol, Silane and Germane

“…Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 7/14/15 1:54 AM 2 : El = Si, 3: El = Ge modified cellulose (1) or amylose (2,3) was used as the chiral stationary phase [5], and the anti podes of 1 -3 were eluted with a mixture con sisting of n-hexane, 2-propanol and diethylamine (980:20:0.2, v/v/v). Detection of the respective enantiom ers was performed with a UV-VIS detector at 215 nm.…”

“…In recent years, there has been an increasing interest in optically active silicon and germanium compounds of the formula type A [1][2][3]. The methods used for the preparation of the (R )-and (S^-enantiomers of this particular type of chiral compounds (center of chirality: Si, Ge) are based on (i) classical resolutions of the respective ra cemic mixtures via fractional crystallization of ap propriate diastereomeric derivatives, (ii) stereo selective chemical transformations of the optically active compounds obtained by the aforem en tioned method and, more recently, (iii) stereo selective biotransformations of suitable racemic or prochiral organosilicon and organogermanium substrates.…”