Formation of Condensed 1<i>H</i>-Pyrrol-2-ylphosphonates and 1,2-Dihydropyridin-2-ylphosphonates via Kabachnik–Fields Reaction of Acetylenic Aldehydes and Subsequent 5-<i>exo</i>-<i>dig</i> or 6-<i>endo</i>-<i>dig</i> Cyclizations
Kabachnik–Fields reactions of various carbocyclic or heterocyclic acetylenic aldehydes together with subsequent Lewis acid catalyzed cyclizations have been studied. It was found that 5-exo-dig versus 6-endo-dig cyclization mode strongly depends on the structure of starting materials. Thus, nonaromatic acetylenic α-anilinomethylphosphonates underwent gold(III)-catalyzed or iodine-mediated 5-exo-dig
Convergent Synthesis of Fluorene Derivatives by a Rhodium‐Catalyzed Stitching Reaction/Alkene Isomerization Sequence
作者:Masaki Nishida、Ryo Shintani
DOI:10.1002/chem.201901519
日期:2019.6.4
the synthesis of fluorenederivatives has been developed by devising a rhodium‐catalyzed stitching reaction/alkene isomerization sequence. The reactions proceed smoothly under mild conditions for a variety of substrate combinations, and extended π‐conjugation systems are also readily accessible by utilizing this synthetic method. Optical properties of the obtained fluorenederivatives have also been