AlCl3-Catalyzed Annulations of Ynamides Involving a Torquoselective Process for the Simultaneous Control of Central and Axial Chirality

• DOI: 10.1021/acs.orglett.6b02480
• Publication Date: 2016-09-21T18:16:34Z
• Authors: Yanyan Yang; Hongxu Liu; Cheng Peng; Jie Wu; Jingyi Zhang; Yan Qiao; Xiao-Na Wang; Junbiao Chang
• Keywords: Annulation; Chirality; Sequence (biology); Closure (psychology); Electrocyclic reaction

A highly torquoselective process for simultaneous control of central and axial chirality by the annulation terminally substituted ynamides with o-quinone methides is reported. In presence AlCl3, a sequence comprising [2 + 2] cycloaddition followed 4π-electrocyclic ring opening 6π-electrocyclic closure leads to stereoselective formation diastereoisomeric 4-amino-2H-chromenes. Terminally unsubstituted undergo AlCl3-catalyzed [4 providing 2-amino-4H-chromenes.