Unexpected Regioselectivity Switch: Organophosphine-Triggered Reactions of Cyclopropene-1,1-dicarboxylates with Aldehydes Shengjun Ni Jie Chen Shengming Ma 10.1021/ol401324z.s001 https://acs.figshare.com/articles/journal_contribution/Unexpected_Regioselectivity_Switch_Organophosphine_Triggered_Reactions_of_Cyclopropene_1_1_dicarboxylates_with_Aldehydes/2398654 With tris(4-methoxyphenyl)phosphine as the nucleophilic reagent, the readily available cyclopropene-1,1-dicarboxylates undergo a ring-opening reaction to generate a Wittig-type intermediate, which would react with aromatic aldehydes to yield (<i>E</i>)-5-aryl-2-(methoxycarbonyl)-2,4-pentadienoates. It is interesting to observe that the regioselectivity of the ring-opening reaction is switched. 2013-07-05 00:00:00 tris aldehyde AldehydesWith Unexpected Regioselectivity Switch Cyclopropene nucleophilic reagent regioselectivity cyclopropene