Synthesis of Enantiomerically Enriched Amino Sulfide Building Blocks from Acyclic Chiral Amino Allylsilanes
摘要:
An efficient synthesis of various protected syn-beta-sulfenyl amides is described. These are prepared from the corresponding enantiopure amino allylsilanes which are in turn obtained from naturally occurring amino acids. The key step for introduction of the sulfur substituent is a diastereoselective electrophilic sulfodesilylation which is carried out with phthalimidesulfenyl chloride. The resulting homochiral beta-phthalimidesulfenyl amines with an allylic sulforated stereogenic center are useful building blocks, as they represent a starting point for subsequent functional manipulations.
[2-(Trimethylsilyl)ethylidene]tris(2-methylphenyl)phosphorane, a modified seyferth-wittig reagent for the stereoselective syntheses of -allyltrimethylsilanes
Synthesis of Z-allylsilanes in high or good yields and with good stereoselectivity is achieved from O-acetylated 1-silyl-3-chloro alcohols promoted by SmI2. The starting compounds were easily prepared from 2-chloroaldehydes and a mechanism is proposed to explain the stereoselectivity of the β-elimination reaction.
Unusual reaction of 2-trimethylsilylethylidenetriarylphosphoranes (seyferth-wittig reagent) with α-methylaldehydes: a novel method for highly cram-diastereoselective addition of vinyl anion equivalent
[2-(Trimethylsilyl)ethylidene]tris(2-methylphenyl)phosphorane, a modified seyferth-wittig reagent for the stereoselective syntheses of -allyltrimethylsilanes
An efficient synthesis of various protected syn-beta-sulfenyl amides is described. These are prepared from the corresponding enantiopure amino allylsilanes which are in turn obtained from naturally occurring amino acids. The key step for introduction of the sulfur substituent is a diastereoselective electrophilic sulfodesilylation which is carried out with phthalimidesulfenyl chloride. The resulting homochiral beta-phthalimidesulfenyl amines with an allylic sulforated stereogenic center are useful building blocks, as they represent a starting point for subsequent functional manipulations.