N. Sakai et al., Mg2+-imidazole-catalyzed self-condensation of malonyl thioesters: Getting tuned for biomimetic polyketide synthesis?, MOLECULES, 6(11), 2001, pp. 845-851
We report that a subtle balance of carbanion reactivity, leaving group acti
vation, and pK(a) of the catalyst is required for efficient self-condensati
on of thiomalonates to thioacetoacetates in up to 71% yield under "biomimet
ic" conditions originally proposed by Kobuke and Yoshida (Tetrahedron Lett.
1978, 19, 367).