Synthesis of cyclopropa[<i>c</i>]indeno[1,2-<i>b</i>]quinolines through a MCR/Staudinger/aza-Wittig sequence

<p>Spirocyclopropanes were prepared from aromatic aldehydes, 1,3-indandione and acetophenones through a halogenation/S_N2-displacement/Michael-initiated ring-closing sequence by a pyridinium-ylide-assisted multicomponent reaction, and their further use was also researched in the construction of cyclopropa[<i>c</i>]indeno[1,2-<i>b</i>]quinolines through subsequent Staudinger/aza-Wittig reactions.</p