Direct One-Pot Synthesis of Phenanthrenes via Suzuki−Miyaura Coupling/Aldol Condensation Cascade Reaction
作者:Young Ha Kim、Hyuk Lee、Yeong Joon Kim、Bum Tae Kim、Jung-Nyoung Heo
DOI:10.1021/jo702001n
日期:2008.1.1
We have developed an efficient cascade reaction, a Suzuki−Miyaura coupling followed by an aldolcondensation, for the construction of phenanthrene derivatives using microwave irradiation. For example, the reaction of methyl 2-bromophenylacetamide with 2-formylphenylboronic acid in the presence of a palladium catalyst and a base provided a biaryl intermediate, which underwent in situ cyclization to
Enantioselective Lewis Acid Catalyzed <i>ortho</i>
Photocycloaddition of Olefins to Phenanthrene-9-carboxaldehydes
作者:Simone Stegbauer、Christian Jandl、Thorsten Bach
DOI:10.1002/anie.201808919
日期:2018.10.26
Visible‐light irradiation (λ=457 nm) enabled the enantioselective ortho photocycloaddition of olefins to phenanthrene‐9‐carboxaldehydes (15 examples, 46–93 % yield, 82–98 % ee). A chiral oxazaborolidine Lewis acid (20 mol %) was employed as the catalyst. It operates by coordination to the aldehyde inducing a bathochromic absorption shift beyond the nπ* absorption of the uncomplexed aldehyde. At long