Han, Ying Sheng, Yin-Jian Yan, Chao-Guo Convenient Synthesis of Triphenylphosphanylidene Spiro[cyclopentane-1,3′-indolines] and Spiro[cyclopent[2]ene-1,3′-indolines] via Three-Component Reactions Three-component reactions of triphenyl­phosphine, but-2-ynedioate, and isatylidene malononitrile (ethyl cyanoacetate) in dimethoxyethane resulted in triphenyl­phos­phanyli­dene spiro­[cyclo­pentane-1,3′-indolines] in satisfactory yields. Furthermore, similar three-component reactions of triphenylphosphine, hex-2-en-4-ynedioate, and isatylidene malononitrile (ethyl cyanoacetate) afforded functionalized spiro­[cyclo­pent[2]­ene-1,3′-indolines] in good yields. dimethoxyethane;Spiro;functionalized;Convenient;yield;spiro;Triphenylphosphanylidene;hex;Synthesi;triphenyl;ethyl cyanoacetate;isatylidene malononitrile;triphenylphosphine 2014-05-16
    https://acs.figshare.com/articles/journal_contribution/Convenient_Synthesis_of_Triphenylphosphanylidene_Spiro_cyclopentane_1_3_indolines_and_Spiro_cyclopent_2_ene_1_3_indolines_via_Three_Component_Reactions/2292022
10.1021/ol5008394.s002