Síntese de Novos Calcogenetos Vinílicos e Calcogenoalquinos Derivados do Glicerol.

Abstract

In this work, it was developed a methodology for the synthesis of vinyl chalcogenides 4 from terminal alkynes 3 and dichalcogenides derivatives 2, obtained from glycerol, using sodium borohydride as a reducing agent and polyethylene glycol-400 (PEG-400) as solvent. The corresponding vinyl chalcogenides 4 were obtained using mild reaction conditions, at 30 °C under conventional heating, in low to excellent yields (14-96%) and only in Z configuration. When the same reaction was performed in presence of ethanol as a solvent, the corresponding chalcogenoalkynes 5 were obtained in moderate to good yields (12-85%). Moreover, the (Z)-(2,2- dimethyl-1,3-dioxolanylmethyl)(styryl)selane (Z)-4a and (2,2-dimethyl-1,3- dioxolanylmethyl)(phenylethynyl)selane 5a compounds could be deprotected to provide water-soluble diols 6 and 7 in 78 and 60% yield, respectively.