Formylation of alcohol with formic acid under solvent-free and neutral conditions catalyzed by free I2 or I2 generated in situ from Fe(NO3)3·9H2O/NaI
Different alcohols were formylated by formic acid under solvent-free conditions in the presence of iodine as the catalyst with good-to-high yields at room temperature. I2 generated in situ from Fe(NO3) 3·9H2O/NaI also catalyzed the formylation of the alcohols under solvent-free conditions. This gives a green and efficient reaction at room temperature, in which the use of toxic and corrosive molecular I2 is avoided.
Thiophilic addition of organolithiums to trithiocarbonate oxides (sulfines). Synthesis of β-oxoketene dithioacetals, 1,4-dicarbonyl compounds, and allyl sulfoxides
Reaction of trithiocarbonates with meta-chloroperoxybenzoic acid in CH2Cl2 at 0°C affords the corresponding S-oxides. These sulfines are relatively stable comppounds which can be purified by chromatography. They react readily with organolithiums in THF at -78°C in a thiophilic manner to give carbanions which are stabilized by three sulfur groups. Hydrolysis affords trithioorthoester oxides. The thermal behaviour of these hindered products has been investigated and new rearrangenrent processes have been evidenced. The former carbanions are soft nucleophiles: 1,4-addition of these intermediates to α-enones was achieved selectively to lead to β-oxo ketenedithioacetals, which are easily transformed into 4-oxoalkanethioates. This 'Umpolung' route allows the formal use of the (alkylthio)carbonyl anion. A thiophilic addition was also observed with allylsilanes in the presence of n-Bu4NF furnishing allyl sulfoxides.
A Novel Method for the Preparation of Thioformates and Thiols by using Thioformimidates
Several new S-alkylated thioformimidates were synthesized and their applications to the synthesis of thiolformates and thiols were investigated.Keywords - thioformimidates; thiols; thiolformates; thioformanilide; Michel-type addition