1309831-72-8Relevant articles and documents
Asymmetric synthesis of (S)-(-)-xylopinine. Use of the sulfinyl group as an ipso director in aromatic SE
Mastranzo, Virginia M.,Yuste, Francisco,Ortiz, Benjamin,Sanchez-Obregon, Ruben,Toscano, Ruben A.,Garcia Ruano, Jose L.
experimental part, p. 5036 - 5041 (2011/08/06)
Optically pure (S)-(-)-xylopinine 2 was prepared in three steps in 52% overall yield. Thus, condensation of the carbanion derived from (S)-4 with the (S)-(E)-sulfinylimine 5 gave a 2:1 mixture of tetrahydroisoquinolines 6a and 6b, differing only in configuration at sulfur. N-Desulfinylation of this mixture gave the diastereomeric sulfoxides which, without separation, were converted into (S)-(-)-xylopinine (2) with loss of the sulfinyl moieties under Pictet-Spengler conditions. This unprecedented ipso electrophilic substitution of a sulfinyl group may have synthetic implications beyond that described in this work.