In the presence of GaCl3, silylenolethers derived from either S-alkyl or S-aryl thioesters are ethenylated at the α-carbon atom with trimethylsilylethyne in high yields. The reactions of dienolates give α,α-diethenyl thioesters.
Use of <i>N</i>-Allylidene-1,1-diphenylethanamine as a Latent Acrolein Synthon in the Double Nucleophilic Addition Reaction of Ketene Silyl (Thio)acetals and Allylborolanes
In the presence of silica gel and water, a mixture of ketene silyl acetals and 2-allyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane underwent 1,4- and subsequently 1,2-addition with N-allylidene-1,1-diphenylethanamine to give delta-hydroxyesters in good yields, where the allylideneamine was successfully used as an acrolein equivalent.