New enantiomerically enriched amino allyl- and allenylsilanes derived from naturally occurring amino acids

Some enantiomerically enriched Z-amino allylsilanes and allenylsilanes have been obtained selectively through the synthetic elaboration of naturally occurring amino acids. Fluorodesilylation with Selectfluor® has been proved as an easy way for preparing allylic fluorides bearing an amino or an amino acid moiety on the lateral chain. In particular, a new unsaturated fluorinated amino acid has been obtained, albeit as a diastereomeric mixture.

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(S,E)-1-Isopropyl-4-trimethylsilanyl-but-2-enyl-carbamic acid-tert-butyl esterC15H31NO2Si[α]D26=-24.5 (c 1.25, CHCl3)Source of chirality = l-valineAbsolute configuration: (S)

(S,E)-1-Benzyl-4-trimethylsilanyl-but-2-enyl-carbamic acid-tert-butyl esterC19H31NO2Si[α]D24=-8.5 (c 1.17, CHCl3)Source of chirality = l-phenylalanineAbsolute configuration: (S)

(S,R)-2,2-Dimethyl-4-(1-acetoxy-prop-2-ynyl)-oxazolidine-3-carbamic acid-tert-butyl esterC15H23NO5[α]D25=-90.8 (c 1.00, CHCl3).Source of chirality = l-serineAbsolute configuration: (S,R)

(S,S)-2,2-Dimethyl-4-(1-acetoxy-prop-2-ynyl)-oxazolidine-3-carbamic acid-tert-butyl esterC15H23NO5[α]D24=-29.2 (c 1.00, CHCl3)Source of chirality = l-serineAbsolute configuration: (S,S)

(R,R)-2,2-Dimethyl-4-(3-trimethylsilanyl-propa-1,2-dienyl)-oxazolidine-3-carbamic acid-tert-butyl esterC16H29NO3Si[α]D24=-168.1 (c 1.16, CHCl3)Source of chirality = l-serineAbsolute configuration: (R,R)

(R,E)-2,2-Dimethyl-4-(2,3-bis-trimethylsilanyl-prop-1-enyl)-oxazolidine-3-carbamic acid-tert-butyl esterC19H39NO3Si2[α]D26=+89.8 (c 1.00 CHCl3)Source of chirality = l-serineAbsolute configuration: (R)