Oxidative Gold Catalysis Meets Photochemistry - Synthesis of Benzo[<i>a</i>]fluorenones from Diynes
作者:Pascal Nösel、Setareh Moghimi、Christoph Hendrich、Marten Haupt、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/adsc.201400969
日期:2014.12.15
AbstractDiynes bearing one terminal and one triarylmethyl‐substituted alkyne were converted into complex benzofluorenone derivatives via a one‐pot process involving a gold‐catalyzed step followed by a photocyclization/oxidation. In the first step an N‐oxide was used to position‐selectively generate an α‐oxo carbenoid at the terminal alkyne which after a regioselective 1,6‐carbene transfer along the tethered tritylalkyne and a subsequent aryl 1,2‐shift furnished tetraphenylethylene‐like derivatives. These intermediates were successfully transformed to fluorenones via oxidative photocyclization.magnified image