Stereoselective synthesis of 2-substituted acrylic derivatives via carbonylation reaction

The carbonylation of 1-alkynes is a versatile tool for the synthesis of important intermediates such as α,β-unsaturated carboxylic acids [1,2]. In our recent work, we have disclosed the synthesis of the important intermediate 2-(trimethylsilyl)acrylic acid and its methyl ester, starting from commercially available trimethylsilylacetylene, in the presence of the readily available catalytic system obtained in situ from Pd(OCOCH3)2/CH3SO3H/2-methyl(diphenylphosphino)pyridine. Reactions are carried out at 80 ºC; methoxycarbonylation reactions allow to obtain methyl 2-(trimethylsilyl)acrylate in good conversions (ca. 93%) and with a branched/linear ratio 95/5, whereas hydroxycarbonylation reactions give lower conversions and selectivities (ca. 53%, and 93/7 respectively). [1] R. Romagnoli, P.G. Baraldi, M.K. Salvador, M.E. Camacho, J. Balzarini, J. Bermejo, F. Estévez, Eur. J. Med. Chem., 2013, 63, 544–557. [2] B.S. Sekhon, J. Pestic. Sci., 2009, 34, 1–12. [3] E. Drent, P. Arnoldy, P.H.M. Budzelaar, J. Organomet. Chem., 1993, 455, 247–253.